The AV123 stuff is nice. I owned one pair of their Onix REF-1 speakers and found them to be extraordinarily well made for the price. It's hard to imagine how you could go wrong with the XLS stuff.
As a Monitor Audio fanboy I also have to point out that the Bronze B line is a screaming bargain right now. SaturdayAudio.com has a great price on the Bronze B line, and a rig consisting of B2's, B Center & Bronze surrounds would come in under $700 before shipping (you'd still need a sub) or about $800 with the Bronze B4 towers (probably wouldn't need a sub with those). I have Bronze B2's in my computer rig, driven by an NAD C320BEE and am very happy with the sound. Plus, I've got an older pair of Bronze 3's- in a small room I found no need for a sub and the Bronze B4's have better bass than my 3's.
Although I haven't heard them yet you may want to check out Hsu Researches speakers. The reviews have been favorable and they come with a 30 day, no questions asked return policy. They're on sale right now direct from Hsu at around $100 per speaker. They have a package with 5 speakers and a sub for a pretty attractive price.
Polk & Infinity also make some nice bookshelves for the price.