Jaesu - very correctly described as the 'music couple'. They're the two best singers in the group, and the few duet parts in their songs always make the fans go 'aww' because their voices complement each other well. They've known each other as long as Yunjae. I read somewhere that they used to be close during their early years, but they aren't as close as before now. I hope it's not true, though. (couple talk 1 2)
^lol Junsu, what the heck are you doing? xP
Jaemin - the fighting pair. Jaejoong is the oldest while Changmin is the youngest, but somehow they always fight. Jaejoong really becomes like a kid when he's fighting with Changmin. It's not in a bad way, 'cos it's pure playing around. I feel bad for Jaejoong, though, as Changmin has gotten more muscular lately and you can tell from the couple talk that he's actually quite scared of Changmin. =X (couple talk 1 2)