We compile this list using the USA region Wii Shop channel, so if you live elsewhere your list will probably be quite a bit different. Please feel free to post your region's findings below as always.
Keep in mind that the list below is a measure of actual sales made recently, not of the total time the game has been available for sale.
Here is the list for the 18th of March:
1 - Tetris Party
2 (3) - My Aquarium
3 (4) - World of Goo
4 - Onslaught
5 (5) - Dr Mario Online Rx
6 (6) - Cue Sports - Pool Revolution
7 (8) - Fun! Fun! Minigolf
8 (7) - My Pokémon Ranch
9 (10) - Brain Challenge
10 (9) - Midnight Bowling
11 (11) - Target Toss Pro: Bags
12 (12) - Defend your Castle
13 (13) - TV Show King
14 (--) - Gradius Rebirth
15 (14) - Wild West Guns
16 (15) - Sandy Beach
17 (20) - Bomberman Blast
18 (16) - Tiki Towers
19 (18) - Final Fantasy Crystal Chronicles: My Life as a King
20 (--) - Family & Friends Party
* (N) - Denotes a new entry on the Top 20
Well the "Big Three" are back in business. As you can see Hudson's Onslaught didn't enjoy very much time at the top of the chart as Tetris Party, My Aquarium, and World of Goo all jumped back up to the top 3 spots again.
The big climber this week was obviously Konami's Gradius Rebirth, which debuted on the Top 20 at #14. We also had another new debut from Family & Friends Party as well at #20. The big dropper this week was Onslaught, which dropped from the top spot down to #4.
Bomberman Blast continues its resurgence and one can only guess how high the game can climb in its second appearance on the Top 20. Tiki Towers is another title that continues to move its way back up the chart as well.
On a more somber note, Mega Man 9 dropped from the 16th spot all the way off the charts this week. We'll have to wait and see if it can manage a return trip to the Top 20 in the coming weeks.