Love Hina. I can't think of any besides that, and, from what I can tell, it still would win even if I did think of more.

rosario to vampire
mahou sensei negima
to love-ru
omamori himari
those are the only ones that i regularly keep up with

Quote from robbit

rosario to vampire
mahou sensei negima
to love-ru
omamori himari
those are the only ones that i regularly keep up with

Ichigo 100%, Love Hina, and Ai Kora are also really good, I have some more but these are my favorites 🙂

Lalala~

Rappi Rangai
Hayate no Gotoku (Does this count?)
Ichigo 100%
The World God Only Knows
Negima!
These aren't in any particular order. I like most the harems I read but these are my favorites.

Trip Fall Die

GAH! My plot doesn't bend that way!

you guys are forgetting ranma1/2 comeonnnnnnnn!!!!! haha

i like negima too haha 😀

Quote from joeymabob

you guys are forgetting ranma1/2 comeonnnnnnnn!!!!! haha

Second that..Ranma's not even like those classic worthless male lead in the harem genre mangas.

..and also Love Junkies..just cuz the girls turned me on.

[img]http://i268.photobucket.com/albums/jj11/obinrobin31/FINISHED2-Roger.gif[/img]
[color=black]The Hidden Agenda=[/color][color=red]Gol.D.Ace[/color]

[color=black]This Week's favourite:[/color]
DoLL (Okado Tatsuya)
Xp

Ai Kora and To-LOVE-Ru

Top class Harem must be Mahou Sensei Negima: one boy Negi and (up-to-now) fifteen girls, with eight in kissing stage already.

Second tier class: First is Happy World. One boy and four(five?) girl, included his aunt and cousin.

Second is Highschool of The Dead. One boy and 2(4?) girls. What it lack in quantity it makes up in quality.

Third is Sekirei. Mwaahahahaha. The number is 6 and rising. The quantity is good and the quality is great.

Fourth is IO. IO is more suggestive than actual stating but the boy look like will handle 3 sisters for certain. It's in his blood.

Fifth is Tsukihime: the number is three and counting.

Sixth is Umi no Misaki (God's Cape). The number is 3 and a half (the littlest sister hasnt made her move, yet).

Seventh is Hayate the Combat Buttler. The number is 6 and counting.
....
Bah. It's hard work to recall all those manga. 😀

I went through this whole thread and the sad thing is...I've read everything everyone has already listed. I don't think I've got one favorite since there are a couple that seem about equal to me. Well, one which hasn't been listed that I did enjoy was Suzuka.

berserkering.deviantart.com
berserkering.wordpress.com

I love harem manga, but gat damn does that shit piss me off sometimes.

The best one from a pure impact standpoint is School Days, no contest.

Listen here
Livin just to keep from dyin
[img]http://imagegen.last.fm/TheDarkTen/recenttracks/imgooley.gif[/img]

My Favourite has to be Umi No Misaki. It has such good characters and a story that has near infinite possibilities make it such a great series and combined with the art make it easily my favourite.

[CENTER][img]http://www.nodiatis.com/pub/4.jpg[/img][/CENTER]

I'm close to neutral on the genre itself because, although tends to steer the story in certain directions, the quality of story can be made good even with stock characters/situations. Because of the increased possibility of cheap gimmicks (like excessive fan service), many harems might suffer in quality, which might be the reason for the bad rap, but anyhow on to answering the question.

My favourite at the moment is probably Negima -- it's the one I've read most often, because I find the story telling better than in LH, RPG-nostalgia, and a lot of the silly humour, but it sometimes annoys me (usually due to excessive fanservice -- I don't mind some, but in some cases, it looks like the author is trying too hard).

Hayate the Combat Butler and Love Hina are next on the list (LH, I rarely annoying -- except that the intro is a slight turn-off IMO --, but I don't think the story telling is as good as in Negima).

I like others (including comedy reverse harems), quite a few which have been listed so far, but haven't read far enough to include them in my favourites, and also dislike a number which have been listed.

A little surprised that someone moved from Negima to To-love-ru (which I'm luke warm about, though it is popular, so maybe I shouldn't be surprised.)

I'm a little surprised that Kimi no Iru Machi wasn't mentioned (it looks like it could become a harem).

Ouran High school host club

that counts as Harem too right?

Ranma 1/2 is my favorite harem manga. I can't stand pretty much every other one I've read, but Umi no Misaki is surprisingly good so far.

That standard ones... Love Hina, Ichigo, Negima... are just awful.

These are my ??Faves??

                                 ..Love Hina..  
                                 ..To-Love-ru..  
                        ..Hayate the Combat Butler..  
                          ..Mahou Sensei Negima..  
                                   ..Ai Kora..  
                             ..Omamori Himari..  
                              ..Otomari Honey..  
                            ..Nagasarete Airantou..