What are some good multiplayer games and consoles?

I think you have your answer already buried in your own post. All of these games are Nintendo. So I would think that Nintendo Wii U would be the most appropriate console.
http://www.amazon.com/Nintendo-Wii-Console-8GB-Basic-U/dp/B0050SVHZO
Don't forget the Wii Fit games which are very family friendly games and solely are for the Wii system.

If your kids are very young Wii is the way to go.

For older kids (8+) a PS3 is a better bet. They have lots of fun "adventure" type games.

Portal is my favorite game ever.
Little Big Planet is fabulous! (Very good for little kids)
Toy Story 3 is really fun
Plants v. Zombies
Rayman
Ratchet and Clank (the old PS2 games are the best ones - make sure you get them remastered for PS3)
Sly Cooper (especially #2 (also remastered for PS3))
Spyro (maybe remastered for PS3)
You can also get the old Sega games for PS3, which are fun if you're into retro gaming.

None of those games have realistic guns. Ratchet and Clank have cartoony guns and the best weapons turn the enemies into ducks or sheep or snowmen.

X Box is the favorite of teenage boys everywhere. Shooting games and sports games are their strong point.

Glados approves of this lovely shoutout for her game! Have some cake!

The cake is a lie.

My kids just d/l Portal ("2", I think) over the weekend, and love it. They used to love LBP.


These were great on the PS2. Haven't seen them on the PS3.

The Ratchet and Clank that came out last month is really pretty good -- it's like the old ones. It isn't as inventive and funny but still okay.

The last Sly Cooper was pretty good too. (I thought #3 was awful.)

Journey, which is download only, is a beautiful little game on PS3 (maybe others). I'll sit down and replay that one whenever I have a few free minutes.

Can multiple people play on the Wii U? How many? Are there any multiplayer games you recommend for the Wii U?

I think 4 people can play on multiplayer games on the Wii. But I believe that you have to buy the extra controllers to play the multiplayer games.

Sports Resort
New Super Mario Bros.
Sonic & SEGA All-Stars Racing
Mario Cart