I've been trying to make a c# program that handles 2d Collision detection and response. I'm using polygons vs polygon but i can't find a good algorthm. Does anyone know any good tutorials or something like that for this type of thing? I've found some c++ tutorials, but none in c#... Thanks in advance!

Can't help you with the c# part, but for 2d (convex) polygons, the separating axis theorem gives you everything you need (static, swept, penetration, time of intersection, collision points and normals). This topic has been discussed ad infinitum in this forum, but I realize with search down the info may be hard to find. A google for 'separating axis theorem' should turn up all you need, though.

Also, I know I've posted links to some standard references in threads that are still on this page, so you might look around a bit.

[Edit: Look in this thread.]

Thanks, the seperating axis therom may be the way to go, I'll try implementing that first, then I'll try response. Thanks for your help!!