I assume you have never watched hentai on a public screening at a convention? ;-) Many of those can be watched for their comedy factor, whether it means what happens in it, or just the quality.
That reminds me, on one of the conventions there was no hentai night planned, so some people just brought their laptops, sat in a corner of DDR/Stepmania room and... started to watch hentai. Before you know it, the corner was filled with people. :-D
Oh and next day the hentai people took over the room and made a more normal screening early in the morning, for a few hours.
Nope, I haven't. I haven't been to a convention yet either though. I'll probably do that at Sakura-con.
There are soooo many hentai you can watch just for the comedy factor alone. What I meant in the above statement was for "good" H if you know what I mean.