Omairi Desu Yo
Complete | yamamoto kotetsuko | 2011 released
Really cliche, but the beautiful art and adorable characters make it insanely enjoyable. I have to admit though that my favorite couple in this is actually Yocchan and Kenji ^_^
Katekyo!
Complete | moegi yuu | 2008 released
I think the thing I love about this manga is that it is a perfect example of a balanced relationship in yaoi. Too often I see a manipulative, controlling relationships where the seme either abuses the uke (w/out consent), or never shows his emotions; leaving the uke as the only vulnerable one in the relationship. This manga shows how the relationship can be perfectly balanced and consensual even when there's a seme and uke in the bedroom.
Konya mo Nemurenai