Despite the crapware we all know exist in the DSiWare shop, if you have patience (and spend a lot of points) there is a surprising amount of good games available. Here I'll list my favorites (of course, may change from person to person). Disclaimer: I like puzzle games ;)
I know, I know, it's a tower defense game. But what a tower defense game! This game had me glued to it until I finished all 30 levels. Developed by the guys behins Star Fox, and costing just 500 points, it's a great game to have.
A great dimension-changing puzzler by Way Forward, and one of the first good DSiWare games. Highly recommended.
This game took long to get me interested in, but when you grasp its concept it's pretty addicting. Another great game for puzzle fans.
An excellent platformer by Way Forward. It's 1200 points, but it could be in a cartridge for sure. A great 16bit-style platformer with great gameplay, animation, and even better music. Play this with headphones.
The Art Style series continously delivered great puzzle games (with exception of Zengage) with a lot of different concepts. In this game, you have to cut paper and make cubes. Yes, you heard it right. It's better to watch a video to understand it. It's a very challenging and cool game.
One of the first DSiWare games, Aquia is a very good, but simple, puzzle game. With only 2 modes, there's not a lot of variety, but it's a good game if you like puzzle games.
