Reaver - Non-magic, make sure you know what you're getting into before you buy this.
Exquisite Velium Claidhmore - Also comes in battle axe flavor, and there are worse versions with worse ratios that are cheaper.
Argent Protector - New in Chardok patch. Worse ratio than exquisite for more plat with some mostly irrelevant stats.
Herbalist's Spade - New in Chardok patch. Cool proc, great ratio, crazy price.
Those are the only droppable options besides Narandi's Lance that are better than Staff of Battle. If you're gonna buy one, I'd recommend an exquisite (or lesser version).
Before you buy anything you should consider why you're upgrading your 2hander. If you just want a sweet 2hander, then go for it. If you're expecting to tank with a 2hander, it's not gonna happen - get 1handers with procs.
If you're looking to maximize your dps in a situation where you're not tanking (group with 2 tanks or a raid situation), that's fine, but it's gonna be pretty marginal compared to the overall dps of the group/raid. Cool if you have the plat to burn, but far from necessary. You might also consider going to PoM and getting a
Blam Stick and another non-proc 1h for your OH. Not sure how the math works out on that vs 2handers, I'll leave that to someone else to figure out.
If you're planning on soloing 50+ on a warrior, you'll want
Truncheon of Doom, probably 2
Blood Points and
Silken Whip of Ensnaring. Doubt you'll have much use for another 2hander.