You should definitely check out Love Roma, it's such a great and unusal romance manga.
Quote from Mangascreener:

Most romance stories (not just manga) fall into two basic categories:

1. The story is entirely about the "chase", as it were -- as soon as the characters get together, it's the end of the story and we're supposed to imagine that they live happily ever after. This is the way most romance-themed manga seem to work, where most of the plot is in the difficulty of the pair getting together.

2. The second type of story relies on a lot of melodrama, soap-opera type love triangles, betrayals, cheating, etc. to keep things interesting. The constant threat of breakup hangs over the pair even if the story is ultimately about their successful get-together.

Rabu Roma (Love Romance) is neither of these stories. One day, a student named Hoshino comes up to another student named Negishi and announces that he likes her and wants to go out with her. The story follows their developing relationship without resorting to cheesy melodrama, harems, or any of the usual manga plot devices. The stories are about fairly mundane events -- first date, first kiss, first fight, etc., but the mangaka is very skillful at making these seem interesting (or perhaps the mudane automatically seems interesting because it's different from what we usually expect out of this kind of story).

Wait, can we also recommend some manga not to read? Because some are really blown out of proportion... That means you, Hana Kimi, Hana Yori Dango, and Kimagure Orange Road. Well, it's your decision to read them or not.

Yeah, Love Roma is awesome. Koukou Debut is great too. I'm not too sure about Lovely Complex and Parfait Tic, but my first impressions on them were okay.

Maybe Love Hina if no one's mentioned it yet. I haven't read it myself, but I heard that it was good.