Dolphin became arguably better than the Wii during it's commercial life
But that is an isolated exception. You are generally correct, emulators take a very, very long time to mature. You'll be lucky if an emulator becomes playable during the next generation.
However we do have lots of multi-platform games and for me, the PC is uncontested when comparing the multiplatform releases due to much higher technical capability/flexibility. A regret that I have is that I bought Castlevania Lords of Shadow for PS3 early in the year thinking that it was a console only game but then I saw a PC release - doh! Missed out on playing at ubber high-res and crisp graphics.
PS3 had some damn good exclusive games. Much better than what I have seen from Xbox 360. That's what motivated me to get the PS3. Any game on the Xbox which I would be interested in, already has a superior PC release.
The Wii is a weird exception. Nintendo exclusive game franchises like Zelda, Mario and so forth are excellent and I have been a fan for most of my life. However Nintendo has produced pretty technically crappy consoles for the last couple of generations. Thankfully, the Dolphin emulator matured enough to surpass the Wii limitations within it's life span and made owning a Wii irrelevant. Playing Twilight Princess in full 1080p is freaking sweet and so is Donkey Kong Country returns or Mario Galaxy. On top of that, Dolphin also flawlessly emulates the GameCube but I am yet to experience that first hand (will soon)
I have heard so many bad things about he Wii-U that I am keeping distance until I see what happens. Apparently is in danger of loosing the current console wars and dropping out due to less than expected sales. A generation without an active Nintendo consoles does not sound right to me but they have been mismanaging it by alienating the core fan base the last few gens.