I modded my wii and have pretty much all the top rated games. Out of them I play smash THE MOST, mainly because I was a huge fan of 64 smash though.
I found Zelda TP a really good experience since I played old school Zelda and Ocarina of Time. I also think the follow are pretty good games:
Mario Kart Wii - not much improvement over previous games though
Super Mario Galaxy - reminds me of Mario 64 but somewhat better
No More Heroes - rough around the edges, but will keep you entertained
ExciteTruck and ExciteBots - Fun racing game that's actually executed nicely
Mario Strickers Charged - Mario soccer game that is fun and easy to play
Guitar Hero - I just liked the game
I've also played games like MadWorld, Metroid 3, and Resident Evil. Good games, but I'm not a big fan of fps on the Wii and Madworld is crazy but repetitive to me.