I don't think I can pin-point 10, but a few I always like seeing are Parallels, Redemption, and the one where he snaps Weyoun's neck.
I do find it interesting that my two favorite charaacters on TNG were Worf and O'Brian. Interesting because they were both late additions, never intended to be series regulars. All of their backstories grew out of the stories and situations, instead of being creative with some sort of gimmick, such as the blind guy with the super glasses, the hologaphic doctor, the android who wants to be human, the telepath who feels emotions, the security chief who grew up in a failed colony and was rescued by starfleet. Just a notice.