Yeah, much like with Touhou, Tsukihime and Fate have spawned numerous fancomics with English scanlations. I've read a few doujins here and there; some of them are good, some of them are not. (Note: should do an entry for Touhou comics soon.)
(Note: It's generally not a good idea to read any doujins if you don't want to be spoiled, unless if you've already beaten the games.)
Let's start with the Tsuki doujins, shall we?
Sis-Long-Legs: The girls try to win over Shiki (that happens a lot in doujins) but Sion thinks she and her long legs have an advantage. Very silly, but occasionally hilarious.
Memory of Dreams: This whole series . . . is a blessing. This series . . . is anything but an eyesore. It is beautiful. A must read for anyone who's played Tsuki in its entirety.
Now for the Fate doujins. One of them is actually a fanfic I'll link, but it counts.
Tamate Notes: A series of shorts that are weird, hilarious, or both. When it's funny, it's really funny.
Dear Tohsaka: A fanfic set after the UBW true end said from Sakura's point of view. One chapter long, but extremely captivating. I guarantee one of two things will happen: you will cry, or you will want to hug Sakura. I felt the latter after reading this.
Childcare is War: This was recommended to me by Tvtropes. In an alternate universe, Rin and Sakura summon Archer. Only thing is, they're seven and six, and Archer has to raise them! Trying . . . really hard . . . not to . . . gush over . . . the cuteness . . .
Let's see how my "associates" fare.
"Rumor has it that the kawaiiko rating on xm's blog is off the charts again."
"Can you prove it, Vile01?"
"Why of course, I brought a scouter. Now, let's see what this 'Childcare is War' doujin is like. . . . . . . . GUH! MY GAWD!!!!"
"What's wrong!?"
"The Kawaiiko rating . . ."
"What of it!?"
"IT'S OVER NINE THOUSAAAAAAAAAND!!!!!"
"WHAT! NINE THOUSAND!?!?!"
"NINE-FUCKING-THOUSAAAAAAAAAAAND!!!!!"
"There's no way that could be possible, let me see for my-SO MOE, I'M GONNA DEE-YIHG-EYE!!!!!"
"Hey guys; what's up?"
"Blue Yoshi, the kawaiiko . . . run while you still can."
"Huh? Kawaiiko? Is xm reading the Piffle World arc of Tsubasa again?"
*silence*
"What could be so bad? It could only be another . . .
A CERTAIN ONOMATOPOEIA!"
Proof positive that cuteness can make anyone melt.
