Good 2D Engine ?

You can't really go wrong with HGE if Windows is your target platform.

SDL (Simple Direct MediaLayer) is a really good library. It has everything you need, and what it doesn't there is an extension for. It is also crossplatform, has a wealth of information available, and isn't too hard to use.

SFML is a good alternative to SDL

ArcEngine. The latest version was released yesterday.

LÖVE is a Lua based cross-platform 2D game engine with OpenGL, physics (Box2D), and audio.

Here's my bookmark of some 2D engines / framworks.