What's Your Favorite Doujin Series?!

OMG...there are so many...

I'm pretty sure there's a thread like this somewhere in this section but what the hell..

Giri giri sisters 1-4 and Omake
Maid bride 1-4
Mai favorite 1-6
Tayu Tayu 1-9
Witchcraft
Honey blonde 1-7
Sweetjam~ Akiko-san to isho 1-3
Hatsu inu 1-3
Mizugi Kanajyo
Competing sisters
Costume parfait 1-2
Nakaba 1-2
Marshmellow steady 1-5
Sister's heart
Onee-san to boku


...

I think that's all...I probably forgot a few.

Anything by Gunma is a plus in my book, but probably my favorite, if I had to pick one, series would be SekaxSeka.

Girl Girl Sisters for sure, I really like B38C Loveberry Twins as well. Those are the only full length doujins I have so I'll be reading others recommendations.

Last time I enjoyed Petit Roid and Honey Blonde.

Pink Shock by Yasui Riosuke, currently.

B38C Loveberry Twins
Giri giri sisters
Petit Roid
Slut Girl
Witchcraft
Tayu Tayu

Just from the top of my head.

mmm pink shock and Heisei Sexual Education Reform

Uehiro - Harukyon no Ecchi Hon
Mitarashi Club - Akiko-san to Issho
Fukudahda - Honey Blonde
Raita - Sakaki x Yoshida
Inu - Hatsu Inu
Shinonome Tarou - Swing out Sisters
Bosshi - Ojousama wa H ga osuki

Hinataka Eroero daisakusen de arimasu-Keroro Gunso
a dangerous weapon known as a school uniform-Bleach
Churuya-san 3 - Melancholy of haruhi suzumiya
C.C Assortment- Code Geass
muchi-muchi angel 14 - To LOVE RU

I think the Sailor Moon series from Black Dog rules.
Other than that... lemme see...Naruko Hanaharu's Shoujo Material

... this is impossible for me to answer. I've read nearly 3 thousand or more doujinshis and I gotta say this about the time I used up on it. LIFE WELL SPENT!