A few weeks ago, I took my Wii with me on holidays with a bunch of friends and the games we enjoyed most there were:
Donkey Konga (2): It's a gamecube game, but we actually played it more then the Wii games. Very simplistic game, so also non-gamers can enjoy it. Might require some alcohol for the guys who are not so fond of hitting bongo's and clapping hands, but the girls and gamers who are used to unusual controller methods will instantly like it. Only downside is that for party's you need to have multiple bongo's.
Wii Sports: Well not one to buy as you already have it, but the game we played most of the time when not playing DK2 was Wii Sports. Tennis, Golf and Boxing were played most of the time. While most Wii owners are probably bored of it for a long time already, for party's it's still an ideal game. Easy to learn and makes good use of the Wiimote. It can be a good idea to prepare some mii's for them, cause the guest mii's aren't that great, so most of the time they were playing with the mii's of my family members.
Mario Kart Wii: Mario Kart isn't just about skills, if you're the last player you'll get the best and most fun items, so it's also enjoyable for the players not so good at games. But it's also a game which is very easily learned, so ideal for party's. I brought one Wii Wheel with me, but it's harder to do with the Wii Wheel, so I can't really recommended it for newbies. Some had fun playing with the wheel though, but they usually did better with the nunchuck.
Super Smash Brothers Brawl: Surprisingly not one of the most played game on my vacation, but one of the favorites of the people who had played the N64 version. While it's still pretty easy to pick up, it appealed a little less to most non-gamers then some other games. If it's the only game you're playing I'm sure others will get into the game too however, as it is a great party game, but other games seemed to do better somehow.
Donkey Kong Jungle Beat: While it's not a multiplayer game, this game was fun even to do in turns. Great game to show to your friends and they'll enjoy it if they play it too, but the lack of multiplayer in it make it fail as a real party game. Great for another bongo for DK2 though and great to play alone. (imo best gamecube-singleplayer game ever)
Mario Strikers Charged: Didn't play this too much, it's a decent game for party's, but not as good as some others. The way things work with charged shots and stuff may be a little confusing for non-gamers and soccergame-fans usually seem to like real soccer games like fifa/pes better.
Red Steel: The guys who were more into GTA-like games were wondering if I also had shooter games. So I put Red Steel in it and it appeared to have multiplayer. Because of the annoying controls and because being with two characters only shooting at eachother isn't that much fun, they got bored after about 10 minutes already. So fails as multiplayer game.
bytor said:
I've always preferred the first RRR to the second one myself...although you have to take turns because there's only a multiplayer per se on RRR 2. And anyone that (even sober!) can play either of these two games without laughing needs serious psychological help
It may have been that the jokes didn't work because of the terrible translation, but I can't remember myself laughing because of RRR1, one of the few games I actually bought. Also the question here is which games are the best Party Games, and RRR sucks big time in multiplayer because it's just as average as the single player, but now two can do the same thing when the other is finished... hurray.