Please tell me I'm missing some games that might appeal to me. Listed below in order of importance are the types of games I tend to buy consoles for:

1. Fitness games. Sadly I don't like Wii Fit calling me obese and I dont like games as a service so even though Xbox fitness looks absolutely fantastic I wont buy in if I can't just buy the software outright. 
2. Character Action Games. Wii U definitely caters to my interest here with Bayonetta and the Wonderful 101. I can't think of any examples for the new HD twins that are released yet. As I've played all DMC games except 2 (I played DmC as well) so Capcom's retread this year isn't all that tempting.
3. Fighting Games. Killer Instinct is okay but nothing to write home about. Wii U has Smash Bros which I love. PS4 seems to be lagging behind in this area. I suppose SF5 is exclusive to it but I haven't enjoyed vanilla Street Fighter since the Alpha days.
4. Platformers.  Wii U has them in spades. I can't seem to find them on the new HD twins at all.
5. Rpgs. I don't like most WRPGs cause I don't like boring or slow action combat. I'm also not a huge fan of exploring huge open worlds when there isn't much meaningful interaction.  

If you have to think that hard about it, it's probably not the right time for you. Just wait for a game that you definitely want to play and then get the console that it's on and fits your standards and budget.

Buying a console should never have to be something you justify. You should wait until there are so many games you want that the choice is obvious.

I'm also pretty blah about this generation so far. (I've got particular tastes.) But I'm sure there will come a day that I finally decide the time is right to pick up a PS4. In the mean time I've got my Wii U, my PC, and the ol' backlog.

Dude you sound like a convincing statement would help you buy a Wii U. Well, if you get a Wii U now, you'll have plenty available and even more to look forward to. Wii Fit U is basically the same old thing, and Wii Sports Club is a little, but at least Wii Sports now has online and some other options which add to the fun. Platformers, do I even need to begin? Rayman Legends, NSMBU, NSLU, Duck Tales Remastered, and DKCTF are all wonderful sidescrollers, and 3D platformers like Super Mario 3D World are superb. Even Sonic Lost World and Sonic Boom are average platformers that do offer lots of fun times. You pretty much scraped the bottom of the barrel with character action games. The Wonderful 101 is amazing, and Bayonetta 2 is even better. It also comes with Bayo1 remade for Wii U, which is really cool since it comes at NO EXTRA COST! Hyrule Warriors is sort of a character action game but is cool none the less. Super Smash Bros for Wii U is honestly the best fighting game I've ever played and is one of the best games of all time. It holds the crown for best Wii U game in my books. As for RPG'S, a JRPG by the title of "Xenoblade Chronicles X" is coming out next year that looks extremely enticing. Some other gems on the wonderful console are Pikmin 3, (a strategy game) WindWaker HD, (awesome adventure game 10/10) and Mario Kart 8 which is one of the best racers I've ever played. What to look forward to in 2015?
1. Yoshi's Woolly World
2. Kirby and the Rainbow Curse
3. Devil's Third
4. Splatoon
5. Star Fox U
6. Xenoblade Chronicles X
7. Zelda U
8. The Mighty Number 9
9. Project CARS
10. Another Sonic game
11. Mario Maker
There will probably be more in the near future, too! Also, Wii U is $100 cheaper than both and most consoles come with bundles, which save you tons of money!
If this doesn't convince you, I'd suggest PS4 because it has tons of exclusive content. XB1 has games, but they're either crappier versions of PS4 games or so-called "exclusives" available on PC or XBOX 360

Fighting game:
Guilty Gear Xrd

Plat formers:
LBP3
Abe's Odyssey - New 'n' Tasty
You probably already have Guacamelee.
Rogue Legacy

Well, as you have kinda already said, the Wii U has a good lineup out and coming for you. Wonderful 101, Bayonetta 2 (which includes 1), NSMBU, Super Mario 3D World, Super Smash Bros, Donkey Kong Country Tropical Freeze, and The Legend of Zelda Wind Waker HD are all games you could give a look at and all Wii U exclusives. Upcoming you have Yoshi's Wooly World, Mario Maker, Xenoblade Chronicles X, the new Zelda, and more. So I would say it is definitely the best at the moment for someone of your tastes.

As for the other two, if you have a PS3 or 360 you can play most of the games released for them anyway. Very few 8th gen only games (exclusive or otherwise) on the systems. My advice, wait. You can get the either of the other two later next year for even less money when there are more games to warrant an upgrade.

It sounds to me like you want a Wii U. This is really the perfect time to get one since you'll have an amazing backlog and all of 2015's amazing games to experience as they release. It's ultimately your decision though; go with your gut, and if your gut says to get a Wii U, then get one. If it says to get a PS4/XB1, get one of those. If you're really not feeling the 8th gen at all right now, then hold off until you really desire one of the consoles.

Basically this.

Pretty sure there is not going to be another Sonic game exclusive to Wii U becuase the 3 game deal included Mario and Sonic, Sonic Lost World and Sonic Boom. All of which sold quite bad. 

Not exclusive but multiplat. I also mentioned Project Cars and The Mighty Number 9 which are multiplat