Two Thoughts on Melek
<bland exposition> I haven't been around here in a long time; "real life" keeps intruding on my otherwise idyllic existence for long periods at a time, which irritates me to no end. It's pretty cool to see that this place is still going strong after all this time. Gotta love WC. </bland exposition>
Anyway, my point in posting would be: In the games, I can very much see LOAF's point about Melek just sort of going whichever the way the wind is blowing, which doesn't inspire a whole lotta respect.
On the other hand, from what I recall of the WC3 novel, (with the kind of additional knowledge you can really only get in the printed form) you get the sense that Melek is much more intelligent and even more honorable thank Thrakath, and that his kowtowing to Thrakath and Blair is not that. Instead, under Thrakath he's trying to tread a path to hold on to enough power to influence decsions. Then, when he's out from under Thrakath's grip at the end of the war, he does what he thinks is right with regard to Blair.
So based on that bias, Melek is probably my favorite. Thrakath would probably be the runner up, for his tenacity if nothing else.