Eheims are what I use and I love them. Like most say, more money, but built better and may last longer than other brands. I thought there was a thread a while back talking about the Filstar's and how their up there with the Eheims in quality, but a little cheaper, maybe try a search for that.
I almost bought one of the Eheim Ecco's for my 34gal tank, but ended up getting the low end Eheim Pro instead cuz it was on sale and only like $20 more
. I'd be curious though to see if their as good as the professional line.