Some OUTSTANDING recommendations, thus far. I have to agree about the Spica TC-50's. These things throw a soundstage unlike anything in this price range. I'm often tempted to buy a pair. The TC-60's "improved" upon the TC-50's with deeper bass (a minus in your case) and greater dynamic range (higher spl's, again a minus). To my ear the 50's are better sounding. They're extremely attractive, to boot. Finally, because there's such a cult following, there are still parts available in case the neighbors are gone and you get a little carried away. I don't actually own these speakers, but many of my non-audiophile friends own them. About 10 years ago, my friends would ask me to help them put together a "modest" system. I told them I'd be happy to go with them to listen, but that good sound is highly subjective, so it would be up to them to decide what they could live with. One by one, I would take them to the various audio salons in the sf bay area and all but one of them ended up choosing the Spica's. (The other was a bit of a rocker and picked up a pair of Paradigm 7SE's)
I've not had an opportunity to hear the Triangle Titus', but I bet they're terrific. Another gentleman recommended the Magnepan MMG's...another INCREDIBLE speaker for the money. Any one of these three can be found for under $500 (including stands in the case of the Spica or Triangle). Of course, you could actually get a brand new pair of MMG's for only $50 more than your budgeted $500. Plus, they'll hold their value pretty well as Maggie's tend to do.
That's my longwinded .02. The good news is that there's lots of good bargains to be found in that price range. Happy listening and best of luck!