I only own Nintendo systems, and I have not played my DS actively in months.

Sonic: Sonic Adventure 2 Battle, Sonic Heroes, Sonic Riders, Sonic Riders Zero Gravity, Sonic and the Secret Rings, Sonic and the Black Knight, Sonic Rush, Sonic Rush Adventure

Naruto: Naruto Clash of Ninja 2, Naruto Clash of Ninja Revolution, Naruto Clash of Ninja Revolution 2

Super Smash Brothers Brawl

Mario: Super Mario Sunshine, Dance Dance Revolution

Near Future: Naruto Shippuden: Clash of Ninja Revolution 3:D

I'll list a few well known games I've owned and completed or nearly completed.

Sonic: Sonic Advance, Sonic Advance 2, Sonic Advance 3, Sonic Battle

Pokemon: Pokemon Yellow, Pokemon Gold, Pokemon Silver, Pokemon Crystal, Pokemon Ruby, Pokemon Sapphire, Pokemon Emerald, Pokemon Leaf Green, Pokemon Rangers

Mario: 2-3 of the Gameboy Super Mario Advance games

I will update this when I've gained a few more video games:)