Several good one's mentioned here, and really, I would say go with a good dealer, that can let you demo one.
Right now we have a Redmax, A shindawa and a Tanaka I think. I saw one of the older Kawasaki's sitting in the shop last night (they stopped making that model I think it was the 23)
We have run Stihl's (a long time) and echo's (never liked them as much)
But what I really wanted to say about this thread was the comment about cutting small tree's.
Soundguy may appreciate this a bit as well.
I was in the market for a brush cutter about 90 or so, and was at the shop, and the guy returned the Demo unit for me to try... I think it was a big TORO, something like 50 cc or so, just a hoss... Anyway, he had demo'ed it on his old very run down, central florida fence line, I think they use natural cedar poles that was badly overgrown, and he was saying how nice it worked with that blade, had to clear back every now and then as the overgrowth would be just falling down, and he could tell when he bumped the posts etc, said he had went maybe 100' or so and turned around to admire his handiwork, and how great it looked, and as he stood there, he watched the entire fence fall over. Come to find out every time he thought he "bumped" one of those old swamp rotten posts, he was actually cutting them off..............
I had the experience when we got our first Stihl FS44 and that was a first with the plastic blades. I was doing a new construction house, and proud of getting right in there close to the little 2 gallon boxwoods,,,, Till I realized they were falling over cause I was cutting them off

Hanna was none too impressed with me that day.... back to a line head the next.