My weekly manga's are One Piece, Histories Strongest Disciple Kenichi, Naruto, Bleach, Fairy Tail, Rosario + Vampire season 2 (it's really more monthly). Detective Conan, and HunterXHunter have place holders on that list. I've fallen far behind on Detective Conan, I still like it, but just haven't been following it strictly in about a year. I'll read an issue every so once and awhile. HunterXHunter, well it's HXH, yay for year + long hiatuses.
One Piece, and Kenichi are the main ones I look forward too. Bleach, and Naruto go back and forth. They both start to drag, then start a new exciting part, then start to drag again.
Rosario + Vampire's a surprise as after I finished the anime, and started the manga I expected something much more light hearted. The manga is far superior to the short anime series, and takes the action up several notches. It's also probably the best drawn weekly manga I currently read.