Wow...I guess I'm in the minorty with this one.
Some movies just shouldn't be riffed...Predator is one and so is Alien. When a room full of 7 longtime MST and Rifftrax fans are gathered on a Friday night , drinking beers, all eagerly waiting to see Alien riffed, and noone utters more than a few chuckles on occasion throughout the 2 hour movie...well, I think you get the idea.
Nice try Bill and Kevin. Much better than Mike's Predator riff, but just slightly.