Some people say that this show felt "empty" to them, but I loved this show. Created by Paul Germain and Joe Ansolabehere, who created another Disney show, Recess, this show focused on 13-year-old alien boy, Lloyd, and his life dealing with friends, family, and school. It was a little more sitcom-esque (and slightly more action-y) than Recess, and was more like the Futurama to Recess' Simpsons.
The characters are, despite their jerk-like moments sometimes, very enjoyable. The only character who really annoyed me was Francine. Lloyd was, and always will be, my favorite. He could come off as a jerk sometimes, but he was actually really sweet when they didn't focus on that "jerk" side (depended on the writer).
The plots were like a sitcom IN SPACE!, and they were pretty well-written. My favorite episode was "Lloyd's Lost Weekend".
There are some flaws though. One of the writers has a habit of focusing too much on the "jerk' sides of the characters. Also, the show probably would've gotten better if, you know, Disney didn't cancel it thanks to the whole OSM/ABC Kids switch!
And aside from personality types, a lot of characters share the same voices as the Recess characters. For example, Lloyd is Gus, Eddie is Gelman, Douglas is Rodney and Lance the Pants, Lloyd's mom is Miss Finster, Miss Bolt is Miss Lemon, Brittney is Ashley A., Megan is Ashley Q., Douglas' mom is Miss Grotke, and T.J., Gretchen, and a few others show up to do background characters.
To me, I think this show was the last good OSM show, as the next show to premiere on the block was the abomination known as...Teamo Supremo. But aside from that, LIS was a pretty memorable show. Not as memorable as Recess, but a great show.