What features does the one exclusion have/not have that turns you off?  Is it exclusives?  The controller?  Subscription fees?  Is it simply your feelings for the company as a whole?

For me I always buy Nintendo and Sony.  Normally I buy Sony at launch and Nintendo a couple years in.  I don't buy MS because while I enjoy Halo and Gears, I can play them a couple times and get my fix and only have a GREAT time if I'm playing co-op.  They're a little bit too online focused for me who is a single player guy who loves the local MP of Smash and Mario Kart (main reason I buy the Nintendo systems though I love 3D Mario and Zelda).  MS just doesn't have the charm of Nintendo nor the creativity with their IP of Sony.  Also I hate offset analog sticks and am ecstatic to have the WiiU controllers have symmetrical ones.  Don't like online fees either (I subscribe to + but I have kept hundreds of dollars worth of games and it hasn't even been a year plus the early betas and free trials).  Just my opinion and I'm not trying to troll anyone it's just when I look at MY personal interest in a console MS just never seems to get me excited.

5th Gen - N64/PS1 - Didn't buy a Saturn because I didn't know much about it.
6th Gen - GCN/PS2/DC - Didn't buy a XB because I didn't really care for it. I could play Halo on PC, and I liked Metroid Prime better anyway. I wasn't really aware of the non-Halo exclusives.
7th Gen - I bought them all

8th Gen - Going to go back to my Nintendo/Sony roots. I'll still likely get a Xbone, but not until late in the gen. The main reasons are:

a) I'm tired of all these Halo's and Forza's, I don't feel 2 years is long enough of a period to justify a new racing game because not much will change, and not many new cars will release. Plus, as much as I like Halo, I don't always want to play it, but I feel that's MS's strategy
b) I can't afford it. I like to play online a couple hours a month, with maybe 2-3 month gaps. XBLG is just to expensive, I literally pay over $1 an hour with the system they have. Why pay when PSN is free? Plus, this used game fee. I buy most of my games for $20 a peice, and on XBL, 6 year old games still sell for $35 (Halo 3, Fable 2). I can't afford a system which costs hundreds of dollars, and then $40 a game for annual or biannual releases (what Forza/Halo are atm).
c) Reliability, I've never had a system so prone to breaking as the 360. I bought an extended warrenty with my 360, and ended up with an HDMI model, which has lasted about 3 years so far (opposed to 1.5 years in old models), and it's already breaking. Why buy a One anytime soon if it won't last the gen?
d) Not a dedicated gaming machine. I don't want to pay for a system which acts as a TV HUB (In USA only too, not in Canada). I don't want some fancy Kinect interfact. I don't want a camera pointed at me at all times. So why pay for all this? I'll wait until the price of the console justifies the gaming machine, I'm not paying for gimmicks I won't use.

For this gen I was given a PS3. And as time went on and I learnt more about each of the consoles I was very glad to have been given a PS3 over a 360.

Though not technically two consoles, was a PS3 and PC gamer this gen. I played all MMOs (like Planetside 2), last gen games and other PC exclusives on PC while I played all multiplats and PS3 exclusives on PS3.

GC and PS2: The xbox to me never really had anything worthwhile to play since it ddin't have a lot exclusives that tickled my fancy.

Wii and 360: Actually they all intrigued me. If I had the $ i would've bought all three of them. The only reason why I got the 360 was because I took advantage of the "get a PC for college, get an xbox 360 for free!" deal that went on during the fall of 2011 since I was (and still) in school.

This time I just might stick with my wii U IF the PS4 does get similar DRM policies like with the XB1.

I don't buy anything except Nintendo systems because I have no need to. I don't enjoy third party games nearly as much as first party games and the competition's first party games just don't put up a fight against Nintendo's.

Also, if I really wanted to, I could use my brother's PS3 for games that aren't available on Nintendo consoles.

I started out with both a 2600 hundred and a NES. My uncle gave me his old 2600 one year, and my grandma had the nes for Mario and Pac Man.

I than got a super nes which is what really set me off on gaming. I still to this day think Link to the Past is the best Zelda game. All of my friends owned the Genesis though and I ended up playing that a lot with them. Always taken turns on sonic and there was this old....fighting game we use to play that had a lot of DC comic guys in it....was really fun. A little to young to remember the name.

Next Gen i was pretty much a pure N64 guy. The star wars games, jet force gemini, and golden eye just made me swallow over into it. I was kinda a nintendo fanboy during this gen and didn't pay the ps1 a single drop of life. I don't even think i picked up a dualshock that gen however.....towards the end I really got into PC gaming and ever since that's been my Forte. I started out with Warcraft II, than diablo, Planescape: Torment and starcraft when that came out. (funny thing is i don't care too much for blizzard games anymore....yes i know shoot me for being such a pc guy and not liking one of it's biggest companies)

the ps2 era I got lucky on. My mother won a ps2 in a drawing at the BX (it's like walmart for military people) for valentines day. When i got this though, there wasn't too many games on the system yet and went back to play a bunch of ps1 games.....and I was missing out. Loved MGS, FFVIII, and Legend of the Dragoon. Than i REALLY got into Dark Cloud.....gamecube I wasn't really liking that much. The controller really threw me for a loop. X-Box I didn't own and didn't care too much for except for splinter cell and halo. For those of us who don't remember Splinter Cell was an xbox exclusive for quite some time. Keep in mind though i was pretty big on PC still Warcraft III, Everquest, FFXI...

This gen. I think i owned every console this gen each for a different reason. I bought ps3 first, and it was a backwards compatible one. I had too many ps2 games i still needed to play. I bought an 360 for a few games....mainly halo and oblivion. (it wasn't released on ps3 yet and my PC was getting old) I do however think the 360 was the first console i ever sold....I didn't play it enough and i didn't want a Live subscription. I was moving to japan as well and needed some cash to help with that. The Wii....didn't interest me. I did however buy it for two reasons. I'm a huge monster hunter fan and i wanted MH3.....and i knew my family would like it. about mid generation, i knew my PC was getting old and i built a brand new one. I've actually built 2 pc's this gen as i get money more fluidly now. I must say though I rarely play any of my consoles now and pretty much do 99 percent of my gaming on PC now. The little i do on consoles is do to exclusives and playing with friends in the states. Otherwise i wouldn't be playing dust 514 if it wasn't for a good friend who's going to be the best man at my wedding soon.

EDIT: I rebought the 360 for star ocean 4...... than it came out on ps3 like a year later -_-

Let me just slap these fanboy goggles on you....annnnddd there. Please proceed to enjoy your very narrow and blind faith in one company.

~

Edit: This post has been moderated by TruckOSaurus

Bought:

N64
PS2
PS3
PSP
PSV
360

Given:

XBOX
PS1
SNES
NES
Gameboy
Wii

As far as things this gen, I waited to be given a Wii because, I have not been impressed with Nintendo since the 64. I used to love Mario, Donkey Kong, Zelda, Banjo Kazooie, and the likes, but they just changed. I had friends that had Gamecube, but I never liked the direction they took any of the games. The art direction in Nintendo games is just not appealing to me. I don't want to look at those worlds or characters for any length of time. On top of that, I don't find the gameplay fun or gripping.

Next gen I think I will be narrowed down to PS4 and PSV. It looks like my friends will be moving from 360 to PS4, and that was the only reason I have a 360. I don't think my parents or grandparents will be buying a WiiU, and I only had a Wii because my parents got bored with theirs.

Edit: I just wanted to note that I have a PC, and I perffer that for things beyond what Sony delivers.

Though I currently only own a ps3 I've also owned a Xbox 360 for most of this gen. Got a 360 in 2006 when it was the best choice. Tons of first party and third party exclusives that wouldn't get ported over for years along with the superior versions of nearly every multiplatform game. Then the 360 started going downhill post 2008.

Bought a ps3 later on mainly for god of war 3, but also the other big ps3 exclusives. Many of them disappointed me but there were a few gems such as infamous and valkyria chronicles. Sold my 360 when Microsoft decided casuals were their main audience post 2010. Wii never interested me. I didn't like the motion controls and most of the big games had superior GameCube alternatives, IMO. Only missed out on Mario galaxy and metroid pime 2. 

Currently almost all my gaming is on pc and 3ds so I'm not too excited for next gen consoles. Ill wait till they are cheap unless some exciting new ips come out that are console exclusive.