I'm no fan of Wii U, I don't like the direction of the system and think the games are not as good as past games, and even ignoring the huge hole of third-party titles Nintendo haven't released as many games on it either. I don't think the library's bad overall though, just "good" instead of "great." No real stand-outs yet, but of course there are still some things to come. And I'd certainly rather have it than a PS4 or XBONE.
I'll list all systems I've owned just to put everything into perspective, in the order I like them today:
Wii - giant variety of unique and fun games
Nintendo 64 - a huge revolution, still awesome
Super Nintendo - refined the concepts introduced on NES into great things
Nintendo DS - similar to Wii, big variety, plus lots of RPGs.
Nintendo 3DS - doesn't quite live up to DS but still cool
GameCube - a painful generation during its time, a bit better after the fact
PlayStation 2 - lots of games yet nothing too special
Wii U - this'll probably move up but for now, not impressed
Sega Genesis - definitely not as good as SNES but it still has some decent exclusives
Game Boy Advance - too many ports, but still a few goodies
NES - extremely important to history, but not really fun anymore
PlayStation 1 - never been a fan, most games not worth it today
Game Boy Color - not sure if this counts as its own thing
Game Boy - too primitive for my taste, need colour
Xbox - never really liked anything besides Halo and Fusion Frenzy
Poor Wii U wouldn't even rank if I included non-Nintendo consoles that would look something like this.
1. SNES- Greatest console ever
2. Playstation 1- spiritual successor to SNES
3. Sega Genesis- almost as good as SNES but lacking in a few key areas
4.Atari 2600- classic console that introduced gaming to many and launched some classic franchises plus still tons of fun today
5. Game Cube- tragic underdog, had better 3rd party support than gets credit for but DVD/Online features drag it down
6. PS2- technically better than Game Cube but I didn't have one when they were new so you can swap these around but nostalgia plays a role.
7. NES- Nostalgia alone keeps it in the top ten but in time that will fade.
8. GBA- between the B/C with regular Game Boy and the great e-Reader stuff GBA had the best port of the Best Super Mario Game ever made.
9. DS- Pretty strong library (this includes 3DS to some extent altough that version I never had)
10. Dreamcast As a former Die hard Sega Fanatic I have to hold onto this unsung masterpiece
11. PC- even if you strip away emulators and Steam PC has the largest and most flexible library bar none. What drags it down is WINDOWS sucks, and its competition isn't smart enough to be serious option for gaming plus keyboards are terrible controllers and sure they are customizable but often configuring all those games with all those joysticks is a nightmare.
12. Arcade if you were alive in the 80's and 90's you know what I mean if not poor you.
13. Game Boy (and color) Classic Tetris alone gets it a spot on the list
14. Game Gear (because it can also play SMS and had a TV Tuner it was the PSP of its day)
15. Sega CD/32X Sonic CD and Lunar alone make it a must have but throw in Mortal Kombat CD, Earth Worm Jim, Ecco the Dolphin and even Sewer Shark why not its still fun plus it plays those Karaoke discs
16. PS3- best multimedia machine ever created, best Netflix player top of the line Blu Ray player and plays great video games
17. Sega Saturn, a few hidden gems and arcade hits that still can't be played anywhere else.
18. Commodore 64- just check out the library and if you were a kid in the 80's chances are you had one or knew someone who did.
19. Xbox 360
20. Wii U
by the time you get down to where Wii U might show up **** most have stopped reading and/or caring.