For disclosure purposes, my loyalties lie at Anfield, but as a Yank, I feel compelled to throw my two cents in on this one.
One, haven't noticed it mentioned yet here and I think it may generally be forgotten, but Donovan is fairly excellent as a dead ball specialist. We've seen Beckham have to watch Landon take free kicks, penalties, and corners. I see skeptical non-Americans will shun the description "world class" when describing him, but I have to say that level of recognition should be awarded to him in this aspect. He is pin point accurate with a dead ball.
Two, as a criticism, and despite his image as a primadonna, I think one of the most frustrating aspects of him is that I think he could be more aggressive and selfish. I've seen him pull up and wait for help in situations where I just am absolutely certain that a run at the defenders would yield a scoring opportunity. He has the skill to make slower, Sami Hyypia type defenders look like practice pylons, but he has a disturbing sense of timidity at times.
Third, a neutral point, he is versatile enough to play anywhere in the midfield, in the hole, or as an out and out striker, but I think his touch, his dribbling, his speed, and the accuracy of his distribution makes him best out wide. He can do left and right with equal effectiveness, but you're more likely to see him contributing positively if you can see the touch line within 10 feet of him. As seen with Brazil, he's absolutely devastating on counterattacks, as well, but I'd put him wide if I were drawing up a team sheet.
Anyways, cheers, happy holidays.