Tricky, because budgets are budgets, but, if you save up and get great speakers, they last you a really long time and end up saving you money (trying a bunch of budget ones ends up costing more than just buying the right one once)..
That said...
I haven't heard the PSBs, Cambridge or Ascends ... I strangely have heard 4-6 (that's rare, usually what people list I might have heard one...so much out there now).
I'd go with the Klipsch. I was pleasantly surprised by the RB-41 II's sound.
Some reasons for my choice:
1. Simply a great value
2. Easy enough load to drive for a budget receiver
3. Pretty good sensitivity
4. Good efficiency
5. As far as the horn loading, it's something I really think they have figured out how to do well, I didn't find them to have bad colorations.
Also, can get them on Amazon, so easy to return if you don't like them.
IMPORTANT (Read whole thing, will save you money and aid sound!):
They require a subwoofer, and I'd recommend using restraint on the subwoofer level. The speakers are still small, and if you overpower them with bass you'll lose the midrange "punch" so important to action movies. This is going to be a deficiency with all these speakers, but the important thing to remember is that adding more subbass is usually what people do to cure a lower midrange deficiency.. which ends up making things worse. Most people do like their subwoofers hot (some very hot), but I'd recommend not going beyond +3dB hot and instead turning up the volume. If you have any further questions feel free to ask (or even PM).
Cheers