Fourth with SNES and Genesis was pretty much the golden era for me. Seventh with Wii/360 which was the perfect compliment, was a close second I'd say. 

I want to say 6th because it was the golden era for AA games, but I have to say 7th because that's all I play generally.

5th and 6th

Mostly because of the quality in Jrpg's. (on psx-ps2) Newer generations exist merely of cheap copies of what happened in 5th and 6th gen. It must have been a blast for developers to try out so many new things on the more powerful systems. Everything after (halfway through 7th gen) is just made for money, i.e. how can we create a popular game instead of how can we create an amazing game-experience.
All the remakes and remasters point to exactly that... No real incentive or idea on how to create something as unique as those games were.

5th.

By a long shot.

Every generation, including the early ones, have some excellent games but most of my top favorites are from the 5th generation. Together with what came out on PC during that time, I’d consider 1995-2003 as being the Golden Age of Gaming. Classic after classic, new experience after new experience. Old series would branch into new directions and many new and promising franchises would be made. I don’t remember another time that was as varied and interesting as the 5th Gen. Other generations, mostly the 6th and the current 8th, just continue the paths set by previous generations, which is boring. During the 5th, new games seemed like completely new adventures, every big game seemed like their developers were really inspired, and I mean really inspired, to create magical games that really tried to add something to the evolution of the medium. It’s sad that many discount the 5th Generation simply because it “has blocky graphics”. As if that’s what’s important. The 5th Generation was actually the most inspired age in gaming there ever was.

Sixth, probably not even close to any other gen. It started with the Dreamcast, which was an amazing console, incredible leap in power over what was most popular at the time, PSone. Arcades were still very strong back then and this was the first time we could have arcade perfect ports of games right in our homes. It was incredible. It also ushered in mainstream online gaming right out of the box with the included modem. Probably my all time favorite console, so many amazing games in such a short time.

Then of course you had the PS2, arguably the best console ever by many peoples standards. I was all about DC so it took me awhile to jump in, especially since PS2 had no online play or even an online adapter out of the box but it didn't take long after launch. Had a great lineup of games. Many many third party masterpieces. Also had SOCOM II, probably my all time favorite online game. Nintendo had the GCN, the only Nintendo console I never owned. But I played it plenty, there were great games on it. Never cared for MK DD but Smash, Wind Waker, Paper Mario, Viewtiful Joe, F-Zero, Luigi's Mansion, Rogue Squadron, etc. Lastly there was the OG Xbox which revolutionized gaming with XBL and launched with Halo, which was mind blowing at the time to be experiencing such a masterpiece on a console. Many great games like Rallisport Challenge, Crimson Skies, versions of Rainbow Six and Splinter Cell that looked and played a generation ahead of the PS2 versions, KOTOR, PGR, MechAssault, Riddick, etc.

Only gen that might come close is fifth.

This is really hard.

I can't say much on the fifth generation, it's one of the generations I've experienced the least games. I didn't have many PS games apart from Gran Turismo 2, Driver 2 and Smackdown 2. Winning races by speeding into the corner barriers was one of my few options to advance for the Escudo Pikes Peak Version. Not proud of it, but it worked. It was my last foray on Nintendo games with the N64, where the only noteworthy games I had were Super Mario 64 and WWF No Mercy. I enjoyed the latter a lot, and it still holds up to this day more than any other game on that console.

I think it was with PlayStation 2 when I started to get a foothold on gaming. Those school nights, playing the GTA's non-stop, getting into the MGS games and falling in love with them, playing and replaying unsung gems like The Getaway and Max Payne 1 and 2, loving cars even more thanks to Need For Speed Underground 2, rekindling my love for platformers with Ratchet & Clank, sucking terribly at fighters with Tekken 5... People love to hate on this one for couple of reasons, but it was the one that pushed me farther into gaming.

Going into the PS3 with GTA IV was such a treat back in 2009, later that year discovering the joys (and misfortunes) of online gaming. That year I dove head first into Uncharted, which I have not regretted to this day. College was painful in more than one way, so going back home to play MGO and lose miserably thanks to my 2 Mb internet was quite something. I went more to Gamestop to check out any games I could buy, having a better chance to play stuff I haven't before: Mortal Kombat, Red Dead Redemption, InFamous... A gen with its ups and downs (I'm looking at you, PSN), but it is one I have fond memories going back to.

I still remember the day I went with my brother to Best Buy and he awkwardly picked up a PS4 off the shelf. It was the Arkham Knight bundle, glinting in my eyes. Whatever. It was a gen I'd hate to admit I switched to a more conservative approach in playstyle, avoiding competitive PvPs and playing one game for most of the time. But I also feels like the one I'm having the most fun, as contradictory as it seems. I can buy whichever game I want now, and getting cool freebies here and there.

I can safely say it's the sixth gen the one that is my favorite and has brought me a lot of joy at the time.

Generation 3, and it was all because of the NES.  But it was really much more than that too.  I started gaming before the video game crash, and have been gaming ever since.  But Generation 3 was really a huge watershed moment in console gaming.  Generation 3 had this amazing evolution in gameplay that happened over the course of just a few years.  Early NES games are things like Kung Fu, Balloon Fight and Bubble Bobble.  Basically they are just home versions of arcade games.  But a few years later you have Super Mario Bros 3 and Mega Man 2 and Final Fantasy and so on.  These are much more complex game experiences that are made purely for the home.

Generation 3 is where you have the biggest improvements to gameplay for flagship games.  It is also where you have the creation of the more classic game series than any other generation: Super Mario, Zelda, Metroid, Final Fantasy, Dragon Quest, Mega Man, Castlevania, Tetris, Metal Gear, etc....  The big companies were taking risks.  They were experimenting with gameplay and a lot of great games resulted from that.

Honorable metions:
Generation 4 - It had two great consoles, and they perfected a lot of what was innovated in generation 3.  Generation 4 looks better in hindsight, but Generation 3 was actually better to experience if you lived through it.

Generation 6 - PS2 had a lot of great games.  I've always felt like those early 3D graphics really sucked, and I was never really excited about 3D gaming.  But PS2 figured out how to make it work and a lot of great games came out from this.

Generation 9 - Switch is only 3 years in and already has a ton of amazing games.  I also like that Nintendo is putting a lot of effort into highlighting the indies.  I get my new gameplay from indies, and I get my highly polished experiences from Nintendo and other higher budget games.  There are so many good games on the Switch that it could actually surpass Generation 3 as my favorite generation.  I just have to wait and see how the Switch plays out during the next few years, but it is doing really well so far.

There are so many posts in this thread that I want to respond to but it's all opinions and everyone's experience with gaming and what made each gen special is "in the eye of the beholder".

I guess part of it depends on how you interpret the op. Which gen would you rather experience today, by today's standards or which gen did you enjoy the most while it was still going on? I looked at it as the former.

7th was by far the best

The 4th is a close second for me as it contains my favourite system of all time, SNES, and a worthy rival in the Megadrive. It was the golden age of 2D gaming, and saw the first exciting steps into the unknown future of 3D.

From the Donkey Kong Country trilogy, to the original Starfox and F-Zero, to Super Mario World and Yoshi's Island, it was a magical time.