Time Chasers is among the best of the best episodes of MST3K. This has been one of my favorites since the beginning, and it's a general fan favorite as well. This episode is tops for me for many reasons. The movie itself is not the worst ever (it's ridiculous, yes, but the main issue is it just had no budget)-it's a bad movie but it is still entertaining and even though the crew makes fun of the music, I kind of like it. The hero of the movie is a dorky dude, true, but he is not unlikable or grating like some of the heroes in other episodes. Additionally, the skits with Servo, Crow and Mike are hilarious. Servo and Crow try to help Mike avoid being trapped on the satellite by using time travel techniques to change his future. I won't spoil what follows, you should just watch! The riffing here is great from beginning to end; there are only a couple of dud riffs for me and it contains riffs I use in every day life. :P
Another aspect of this particular episode that makes it so great is the reaction of the director, cast and crew of the film. They have fully embraced the experience and even do events in connection with the show and Rifftrax to sign autographs and meet with fans. It just makes it all even better.
Bottom line: This is a must-see for fans and an excellent starting point if you are introducing someone to the show or embarking on MST adventures on your own. :)