I've used enough different lengths, I'm not sure I can keep track anymore. I think the last three in order were 15ft, 35ft, and now 25ft. The pricing was right about $15, $50, and $25, all from Monoprice. I do have at least one short BJC in the rig somewhere too.
I'm connecting that to a JVC projector, in a room that resembles more of a batcave than not, have spent a few hours the last few days re-calibrating, also with my second bluray player, on a screen that is larger than highfigh's friend's.
The pic is gorgeous, and is honestly the most beautiful my friends, family, or I have ever seen. It looked just as great with the 35 footer, and that was in there for over a year, IIRC.
Read this AH test, and you can immediately see that price does not correlate with performance in the HDMI world.
Check out the Monster HDMI cable for $250 at 10m that fails 3 out of 5 tests. BTW, the 5th test is just for the hell of it: the 120hz signal that doesn't even exist for us in the AV world.
http://www.audioholics.com/education/cables/long-hdmi-cable-bench-tests/hdmi-cable-testing-results