List your favorites so we have an idea of what to work with.

If you're a girl (as I assume) and like shoujo, I would say Fruits Basket as it's one of the most popular ones. Drama con isn't a bad one either, although I've only seen like 3 volumes (and it's American). For a harem love comedy, I recommend Love Hina as it's one of my favorite manga ever. Mahou Sensei Negima by the same mangaka is also great. Death Note was incredibly popular. Actually I also like all the ones Abyssal said. I would recommend you look online for scanlations to see which mangas you like enough to buy.