Quote by nixhelIt depends on what kinds of genre you like. The following titles I personally like are listed below based on genre.

Shojo:
Kareshi Kanojo no Jijou ("Kare Kano")
Tenshi Kinryoku ("Angel Sanctuary") - this one takes a lot of liberties with the actual angelic hierarchy; not your usual shojo fair
Fruits Basket

Shonen & Other(?):
Rurouni Kenshin
Chrno Crusade ("Chrono Crusade")
Ma-Je ("King of Hell") - technically, this isn't manga but mahwa (Korean comic), but it's pretty cool
Mugen no Junin ("Blade Of The Immortal")
PEACE MAKER Kurogane

Supernatural:
xxxHOLiC

Horror:
Mantis Woman - it's a single vol manga by Senno Knife and published by where-are-they-now I.C Entertainment (Studio Ironcat)

Some fans recommended me other titles like "Gantz" and "KAmi Kaze", the latter by Shiki Satoshi. There aren't any English language releases though unless you can read Taiwan Chinese "Gantz" the anime is relatively faithful to the manga storyline (some parts had to be omitted because of time constraints), so you can get a pretty good idea about some of the chapters from there. "KAmi Kaze" is, quoting a fan, "typically shounen and predictable", "lotsa fights and blow-ups", "drawing quality is excellent" and "it's about a special race of people who are fighting against one another and they each command a power of the elements like Fire, Water, Wind and Earth. The male lead is the guy who commands Earth and the female lead commands Water."

Darn it! I can't read mandarin! Your description is sooooo good too, thanks for the list of the other stories (supernatural ones scare me *shivers) I've heard of some of the other ones and seen them and they do look good!Thanks a lot for the advice! * sprints to the closest manga book selling shop... thing 0_0* Thanks for posting in my thread!