What series do you think should have more doujinshi/hentai?

bah, the majority of series mentioned in this thread have plenty enough hentai as is. Either you lot just aren't looking well enough, or you're just unsatisfied with the pretty massive amount of 34s already available (and in response to the person who said there's not enough non-Hinagiku Hayate doujins, for the record, I have seen pretty nice ones depicting Maria, Saki, A-tan, and at least a few others). Personally, I think if a series has at least one doujin product (manga or CG) that's drawn nicely enough, and features a variety of sexual acts involving at least said series' most prominent/sexiest character(s), acts which can go as far as (if I'm really lucky) anal or even DP, I'd easily consider that satisfactory enough. That said, here's my listing of series that are in no way matching their porn up to their characters' level of titillation (and this is just off the top of my head):

Atelier series (sans the first couple of games)
Azure Dreams (though this is a criminally overlooked game altogether)
Bokujou Monogatari (better known as Harvest Moon in the west)
DearS
ef*
Girls Bravo
Gosyusho-sama Ninomiya-kun
Karin
Kiss X Sis
Legend of Zelda (at least when it comes to stuff NOT drawn by a westerner)
Needless
Omamori Himari
Seitokai no Ichizon
Shuffle!*
Shukufuku no Campanella*
Tears to Tiara*
Yami to Boushi to Hon no Tabibito*
Zatsune Miku (so far as Hatsune recolors go, I particularly like her)

*Asterisks are noted ironies in that those series were initially H-games to begin with, albeit extremely vanilla. Though, in the case of Tears to Tiara, the art-style of the PS3 game/anime had a complete overhaul from the original eroge (in an ironic twist, I think the newer designs actually look MORE suited towards standard eroge fare now, making it all the more sadder that nobody's drawing them doing the nasty... and this is a Leaf game, for Christ's sake T_T).

Please note that I didn't list MM!, or any other series from the past season, as it's too early to call at this point (even in light of a Comiket having just occurred). Although I can say MM! has had a rather disappointing show on Pixiv thus far. T_T I'm also very tempted to list Vandread, Erementar Gerad, and Kanokon, but when I think about it, they've had a few decent doujins to their name (most notably from Studio Kimigabuchi, Red Ribbon Revenger, and Shikishima GunTool, respectively). It's a shame more series can't be like To Love-ru, which had a crapload of doujin before an anime adaption was even made (though Medaka Box might be coming close), and today easily stands as one of THE most 34ed franchises I've seen.