http://ggpo.net
Setup should be fairly easy, all you need is the appropiate ROMs which are pretty illegal but still fairly easy to find over google ;P
You can find me there playing a lot of Street Fighter 3: 3rd Strike or SF3:3s or just 3s (I'm not good there) and the occasional game of Super Street Fighter 2 Turbo or just Super Turbo, ST (I'm utter garbage there q: ). I can provide you with the ROMs for these 2 games, just PM me.
The great thing about GGPO is that you can play against people from all over the world and as long as you both got halfway decent internet connections, it will appear lagless (ping doesnt matter much). I don't know how it works exactly, but afaik the game will skip non-synched frames (you cant see that if the connection isnt horrible) rather than delaying the inputs (which is the case in Street Fighter 4, where it is impossible to play a decent match against anyone outside of Europe, and sometimes even inside of Europe the lag is ridiculous).
Hope someone is interested in playing some casuals with me while sitting in Mumble listening to my rage ;D
(Flame post from Lim-Dul incoming in T minus 5, 4, 3, 2, 1...)