That would really depend on how important bass is to you. Others have recommended tower speakers with self-powered subwoofers. But, the ones that I've heard almost all produced unbearably boomy sound and box resonance. Those speakers might not have been properly setup, but the main speakers are rarely placed where the bass is ideal. Full range floorstanding speakers can have better integration with the highs/mids than standmount, but you lose the flexibility that a standmount/subwoofer combo gives you.

This pretty much leaves you with floorstanding speakers, and I can tell you that most of the sub-$1,000 floorstanders that I've heard have problems with box resonance that make them sound boomy and bloated in the bass. This creates problems in the midrange and highs as well because the bass drowns everything else out. The standmounted versions of those speakers generally did not do this. If you can go over $1,000 for a pair of main speakers, your odds of finding a floorstander with minimal box resonance increase. For starters try out B&W, Energy, and Boston's floorstanding models. If you can go higher in price, add Paradigm's Studio series and Dynaudio's Audience series to your list.

As you go further down into the bass range, the more susceptible those frequencies are to acoustical problems in your room. (There is such thing as too much bass if your room's a problem) These types of issues will not always be apparent in a dealer's demo room because those rooms might be acoustically controlled or the speaker characteristics don't present any problems there. Therefore, you should arrange to home demo whatever speakers you're most interested in. That way you will hear first hand what they will sound like before you break out your credit card!