I'm looking out for similar games to you. I used to like Fuzion Frenzy on the XBOX for having 3 or 4 mates round for a few beers and a laugh, but have yet to find anything as fun yet on the Wii. Also Crash Team Racing used to be a good laugh on the Xbox so i'm looking forward to Mario Kart when it comes out - whenever that is!!!
My friend at work says that Mario Party 8 has got a few good multiplayer games but i've yet to play it myself.
Oh (and just went I thought i'd got fed up with Wario Smooth moves), a few of my mates were round on Saturday night and tried the multiplayer, and although you can only use the one Wii controller is was actually a good laugh. There is one particular game that you can stitch up your friend by choosing them and what type of game you want them to play (so obviosly we kept going for games that they didn't want). Have you tried that yet?