Akatsuki manga has some nice manga projects going.
J-comx does the translation to a personal favorite, Chrno Crusade. Also did most of the Azumanga Daioh manga translations long before the anime hit.
love hina party hosts several series.
I's manga scans. See where manga scanslations began. This was the project that started it all, and it's still there for you to download. (along with two other pages devoted to two other excellent series, love hina and DNA, be sure to read them all)
Manga project is probably the largest scanslating group, their website has tons of good manga for you to download.
And finally, be sure to go to www.shonenjump.com and get a subscription for only $30 a year if you like mangas. Remember, fansubs are free, don't buy them on ebay, if you catch someone selling them, please report them to ebay.