Ratchet and Clank: Going Commando is my favorite game for pure fun. There are many improvements on the first, including some RPG elements that add more meaning and consistancy to the gameplay. The controls are tighter, and being able to strafe is nice. There's also a challenge mode that adds replay value, and some fun mini-games. The weapon upgrades are great, and really feel like big, meaningful changes. The graphics are excellent and the music is cool, and the gameplay remains fun no matter how many times I've played it. There are also some funny scenes, and the plot is more complex than in the first game. Not to mention there's plenty of things hidden in the game world to find. It's just tons of fun.