Of all the melee ATs, I tend to prefer the classic scrapper. With two caveats: the scrapper needs to have a secondary that has at least a mild taunt aura, and be defemse based. Scrappers have the same 45% defense cap as everyone else, but with a resistance set they have a 75% limit where tankers and brutes have 90%, a noticeable drop off. Willpower is the set that tests the rule; it has enough going for it that it doesn't need to hit any softcaps. Secondaries like Shield and Energy shine on scraooers.