For me the early 90s with the new technology came a lot of experimentation and new kinds of games. For example one of my favourite developers Bullfrog made game

For me the early 90s with the new technology came a lot of experimentation and new kinds of games. For example one of my favourite developers Bullfrog made games like Populous, Syndicate, Magic Carpet, Theme Park, Dungeon Keeper. All radically different game styles and all excellent games. The late 90s and 00s to me was all dominant single games (e.g. Starcraft, Quake, Halflife). A lot of it was about having the latest graphics, with big studios winning. And spinoff games were done with an 'engine', which often made them look/feel/respond similar to the original. You also saw a lot of sequels and series taking over from new game concepts because of this. And most of them were in a few genres (FPS and RTS especially). I agree its a good time now though, we are so flooded with different types of games that you have to do something interesting to get noticed.