I would say get either the Wii or the PS3, and forget the 360, as nobody should have tp put up with high failure rates. Even if it has got a warranty, you can avoid the hassle by getting the other 2.
PS3:
Blu-Ray and full HD output, even if you don't have an HD TV now, it's highly likely your next one will be.-Nothing can ever be future proof, but HDMI means it will stay relevant until UHD comes out, which won't be for a very long time. Also, if you're a PC gamer, it's likely your monitor supports DVI, and a resolution of at least 1600x1000 and 60hz, so you'll be able to support 720p at 60fps anyway. With the correct cable, which I found for about £15 on amazon.co.uk
Full compatibilty with PCs and PSPs (possibly phones not sure) via wireless. -This is incredibly useful if you have music/video on your PC, you can just stream it wirelessly from your PC. All that's needed is firmware 1.80 (I think, which supports media servers, and a wireless card for your PC, although it worked for ours, with just a wireless USB dongle thing, for the PC, no need for anything with the PS3 as it has Wifi and Bluetooth.).
Motion Sensing- everyone knows the Wii has it, but so does the PS3. Although it is not used as much as it is for the Wii, if you prefer a more relaxing experienc, and don't want to be waving your arms around, then you may prefer that. Also, it makes for a fun experience in both driving and flying games.
Mouse and Keyboard support -As you specifially asked this, the PS3 supports any USB Keyboard and mouse (and headset for that matter), so if you want to get RTS or FPSs for it, you'll still be able to use that setup. And you'll have the advantage of console gaming, where there is no need to worry about the requirement of the game, it was designed to work on your console. Except where the 360 Core SKU is concerned.
Sony's software lineup -While Microsoft may concetrate on gamers aged 18-30, and Nintendo on 5-13 and 35-100+, Sony over the past 2 generations has tried to provide games for a large audience. Here's a quote from Insomniacs Brian Hastings:
"One of Sony’s biggest advantages is that it has strong franchises in every genre. Whereas Microsoft’s successful titles are mostly M-rated, and Nintendo’s are mostly E-rated, Sony has a big list of hit titles across the spectrum. When a 30-something gamer (like me) goes to buy a game console, it’s a lot easier to justify the purchase when there are games he can play with his kids as well as more mature stuff.
To Microsoft’s credit, they are doing a good job of catching up. The acquisition of Rare and the development of Viva Pinata have helped to broaden their spectrum. But it takes time to build a franchise, and Sony has been building their suite of titles for over a decade. Consider the breadth, success and critical acclaim of some of their exclusive properties: The Getaway, God of War, Gran Turismo, Hot Shots Golf, Jak and Daxter, Killzone, Ratchet & Clank, Shadow of the Colossus, Singstar, Sly Cooper, SOCOM, and Twisted Metal. These are all million-plus sellers worldwide that are either already announced or likely to appear on PS3. Add to this Sony’s new line up of first-party titles, including Heavenly Sword, Lair, Motorstorm, Resistance: Fall of Man, Uncharted and White Knight Story, and they have an even deeper and stronger line-up than what they had on PS2"
PSN -1 word, FREE. When a PC gamer like yourself comes to playing online, you may be shocked when it comes to having to pay (a total obsurdity) for online with xBox. with PSN you don't. Here's another quote from Brian Hastings:
"Among all the talk about the price of Sony’s console, I almost never see anyone mention the significance of Sony’s free online service. Xbox Live Gold costs $70 to sign up for 1 year, or $20 for three months. You can renew your membership for $50 a year. So if the Xbox 360 stays around for five years, you’ll be paying 70 + 50 + 50 + 50 + 50 = $270 to access features that Sony gives you for free."
On top of that, Sony is working on a movie on demand service for PSN, and considering they're one of the world's biggest film studios, it's likely they'll do a good job of it.
Backward Compatability -as you don't mention that you have any last-gen consoles, with is a HUGE bonus. Even the EU version of the PS3 has ~90% backward compatability, and frankly the only game I'ver ever had any serious problems with (out of a pretty large amount of games) was Wipeout fusion, and that was with 1 track. So you'll be able to take advatage of the PS2s game library, which is quite possibly the biggest ever. I think there is about 1800 games or something like that, although not all of them any good :P
Wii
Different experience -I hadn't played a Wii in my life until a few days ago, and my word was it totally different from anything I had done before. However, as I don't own one, I can't vouch whether this will still be a bonus after a year of playing it. Personally I can't think of anyhting I've used for over a year that still has that "Wow" factor.
Nintendos software lineup -Nintendo being the longest in the market (out of Sony, Microsoft, and themselves) has built up some pretty impressive franchises. So if you into any of them, then the Wii is for you. Especially as the Wii supports Gamecube games, andwith Virtual Console, you can play games that you may not have had the chance to play. So if you like Zelda etc. then you may want to consider the Wii.
Price -I'm gonna go with UK prices here, as I have no idea what country you're from. The PS3 is about £400. The 360 Premium about £280, and the Wii about £180, so you'll be saving a fair amount of money. However, there are a few extra costs. The Wiimotes are not rechargeable, so unlike with the SIXAXIS you'll be paying extra for batteries. Also, (according to amazon) the Wiimote is slightly more expensive, and if you want to get 4 Wiimotes with nunchucks, it's a massive £180, when 4 SIXAXIS would cost you £120. Although you'd actually most likely need 3 SIXAXIS: £90, and 3 Wiimotes + 3 Nunchucks: £135. So you may want to consider those extra prices. Also, if you want to play VC games and GC games, you'll need a classic controller (about £15). Also, you may want to upgrade the frankyl abysmal storage space, by getting a 2gb SD card (about £15).
Wifi -Like the PS3 (and unlike the 360) the Wii has Wifi, so less hassle to set up an internet connection (presuming you have a Wireless Router).
Size -If you need more space, the Wii is easily the smallest of the 3 consoles.
Online -The Wii supports a large variety of online services, and like PSN, is free. A quote from amazon:
"The Wii Channel Menu will be the first screen shown on the television, as it easily integrates itself as part of people’s everyday lives. The Wii Channels are: Disc Channel, Mii Channel, Photo Channel, Forecast Channel, News Channel, Wii Shop Channel, Internet Channel and the Wii Message Board."
Hope that helped