At about $100, there are still quite a few good choices: decent volume and sound quality.
I'd suggest getting either the M-audio AV30 or AV40.
The AV30 is $94 on amazon:
http://www.amazon.com/M-Audio-Studiophile-Professional-Reference-Speakers/dp/B000SDLNKA
The AV40 is a little over budget @ $134.
http://www.amazon.com/M-Audio-Studiophile-AV-Powered-Speakers/dp/B000MUXJCO/ref=sr_1_1?s=musical-instruments&ie=UTF8&qid=1283575332&sr=1-1
Either will have great bass - especially for no sub... and have dedicated silk dome tweeters for the highs.
They both are bookshelf style with internal amp of course... and very compact in size. No sub means no extra cables everywhere...
...
If you are interested, there's also great deals to be had on your local craigslist or kijiji. Check them out - but make sure you know what you are looking for and also that the items work.
HOpe this helps!