I'm assuming you're talking about a keeper league...
Abreu and Helton. Easy. Damon's the next Trot Nixon. He's on his way out. He may play til he's over 40, but he won't produce like he has. Gone are the days of 20 HR seasons.
Damon and Helton are both around 35 years old. Abreu is 34. Abreu vs Damon is close, but I'd have to give a slight edge to Abreu just for the age difference.
If you're not talking about a keeper league, I'd still take the same two.