I've actually watched all of Lamune, half of Ai Yori Aoshi, and most of Mahoraba. Unfortunately, all three were a bit too dull in my opinion, I stuck out until episode 18 or so for Mahoraba because the main female character's MPD were fun to watch but in the end there wasn't enough substance in the plot for me to keep watching.
I pretty much feel the same about Ai Yori Aoshi as well although I enjoyed Mahoraba a bit more.
Tsukuyomi Moon Phase and Karin sound good, I've read a bit on the former before but Romance wasn't listed as one of it's genres so I ended up skipping it.