FYI. Not perfect by any means and some games crap out when things are wider than 16:9. I suggest spamming the creator's forums to make yourself heard if that is your thing.
Feel free to list others.
Project 64(Nintendo 64) - Force aspect ratio.
http://www.pj64-emu.com/
NullDC(Dreamcast) - Extra Geometry
http://www.emudev.org/nullDC-new/
Dolphin(Gamecube, Wii) - Widescreen Hack
http://www.dolphin-emu.com/news.php
