I don't think I've played 20 wii games...shows you how much love I have for my wii.

1. Super Mario Galaxy
2. Mario Kart Wii
3. The Legend of Zelda: Twilight Princess
4. Wii Sports
5. Resident Evil 4: Wii Edition
6. Metroid Prime 3: Corruption
7. Super Paper Mario
8. Super Smash Bros. Brawl
9. Punch-Out!!
10. Call of Duty: World at War
11. The Conduit
12. Grand Slam Tennis
13. Mario Strikers Charged Football
14. Resident Evil: Umbrella Chronicles
15. MadWorld
16. Wii Play
17. Wii Fit
18. The Godfather: Blackhand Edition
19. Excite Truck
20. Shaun White Snowboarding

1. Super Mario Galaxy
.
.
2. Metroid Prime 3
3. Zelda TP
4. No More Heroes
5. SSBB
6. RE4 Wii Edition
7. The Conduit
8. Wii Sports
9. Red Steel
10. HOTD Overkill
11. RE Umbrella Chronicles
12. Zack & Wiki
13. MadWorld
14. Super Paper Mario
15. Boom Blox
16. Scarface
17. MOHH 2
18. Okami
19. Tenchu SA
20. Guita Hero 3

Just too many great games to pick from  I could of easily done 50 great games.

Here is a list in alphabetical order.  I might go back and rank them later.

Battalion Wars 2
Dance Dance Revolution: Hottest Party
Fire Emblem: Radiant Dawn
Guitar Hero World Tour
LEGO Star Wars: The Complete Sega
Metroid Prime 3
Naruto: Clash of Ninja Revolution
No More Heroes
Prince of Persia: Rival Swords
Rayman Raving Rabbids
Resident Evil 4: Wii Edition
Super Mario Galaxy
Super Smash Bros. Brawl
Tales of Symphonia: Dawn of the New World
The Conduit
The Legend of Zelda: Twilight Princess
Trauma Center: Second Opinion
WarioWare: Smooth Moves
Wii Fit
Wii Sports

Lots of good games that didn't make the cut (at least another 20).  There is probably about another 5 that I will likely rank in this top 20, but haven't purchased them yet.

I can't believe so many of you put Wii Play on your list. I think that's been in my Wii for a total of 20 minutes.

@Figlioni: I wouldn't put it there, but there are a few good minigames on Wii Play (certainly worth more than 20 minutes), and some people don't have large enough collections of games to not include it. I tend to rate my games on a curve based on price, and if you figure Wii Play is only $10, there are a lot of $50 games that I don't think are 5 times as great as Wii Play so I can certainly understand how it would make some people's list.

For a $10 game that had the awesomeness that was tanks, it easily deserves a spot on my list. Besides, I've had it in my Wii a lot more than I can say for a few other titles..

The most played games in my family (five years old son, wife and me) are these:

20 Cooking mama
19 Guitar Hero Metallica (I just got it)
18 Lego Indiana Jones
17 MySims
16 Trauma Center
15 Raiman Ragin Rabbids
14 Resident Evil the Umbrella Cronicles
13 Excite Truck
12 Lego Star Wars The Complete Saga
11 Mario Party 8
10 Bully
9 Lara Croft Tomb Raider Anniversary
8 Call of Duty World at War
7 Mario Strikers Charged Football
6 Guitar Hero Legends of Rock
5 Wii Sports
4 Mario Kart Wii
3 Resident Evil 4
2 Super Mario Galaxy
1 Zelda Twilight Princess

My list always only include games i actually played from start to finish:

In that order:

1. Resident Evil 4: Wii Edition

2. Super Mario Galaxy

3. The Legend of Zelda: Twilight Princess

4. Punch-Out!!

5. Final Fantasy Fables: Chocobo's Dungeon

6. MadWorld

7. ExciteBots: Trick Racing

8. New Play Control! Pikmin

9. Super Paper Mario

10. Mario Kart Wii

11. Wario Ware: Smooth Moves

12. Bully: Scholarship Edition

13. Scarface: The World is Yours

14. The Godfather: Blackhand Edition

15. de Blob

16. Zack & Wiki: Quest for Barbaros Treasure

17. Tales of Symphonia: Dawn of the New World

18. Guitar Hero III: Legends of Rock

19. Klonoa

20. Prince of Persia: Rival Swords

It was actually pretty hard to rank those games in order and make my list accurate since i like all of these games alot.

1 Disaster Day of Crisis
2 Zelda Twilight Princess
3 Super Mario Galaxy
4 Fire Emblem Radiant Dawn
5 Little King Story
6 Super Smash Brothers Brawl
7 The Conduit
8 Metroid Prime 3
9 Zack & Wiki
10 Okami
11 Onechanbara: Bikini Zombie Slayers
12 The Godfather: Blackhand Edition
13 Resident Evil 4: Wii Edition
14 Wii Fit
15 Tenchu
16 Endless Ocean
17 Dancing Stage Hottest Party 1+2
18 Eledees
19 Mario Kart Wii
20 Kororinpa 1+2

Right now I think I could fill a Top 40 Wii Games list with further good games like Job Island, Overlord Dark Legend, Sonic Unleashed, Tomb Raider Anniversary, Trauma Center, Anno: Create a new World and so on ...

Games I didn't like:
Madworld
Star Wars the Force Unleashed
Tomb Raider Underworld