I had a ton of cash to blow, so I decided to go for the Bose Companion 5 and I've been thoroughly impressed. I'm sure I didn't get the best for the money spent, but the USB audio and compact size were beneficial, and I've been very happy.

That said, I had the Logitech Z-550 speakers before (one step above yours) and they were amazing, so I suspect those will be very good to you as well.