I always thought Mon-El was sort of boring, despite his genuinely exciting backstory. As far as I can tell, he emerged from the Phantom Zone after 1,000 years, dusted himself off, and said "Glad that's over", and just carried on. Your question did make me think about which member of the LSH I really liked, and I started to realise I don't have as much affection for any of them as I thought. I sort of liked Invisible Kid, because I always liked an Invisible Man story, but let's face it, he never did much. I sort of liked Ultra Boy, because he was a bit volatile and also had the most wonderful limitation to his powers ever, a bit as if I were told that I could either chew gum or walk at the same time. Finally, though, I plumped for Chameleon Boy, who was consistently depicted as a very pleasant character, and also made fun of Spider-Man once. He's got to be the favourite. Why recent depictions of him make him look so sappy is beyond me.
Anyway, given that nothing is funnier than a comic book panel taken out of context, here's an offering from Gone & Forgotten:
http://www.ape-law.com/GAF/pages/when-the-legion-was-young-and-innocent.shtml