Hi,
Loudspeakers are like most things electrical, you get what you pay for. So it's worthwhile taking some time to choose the right ones. The best way of choosing speakers is to listen to them before parting with your cash. Assuming you want to listen to music on them take a couple of well known tunes with you to and listen to as many different speakers as you can. That way you'll know the speakers that sound the best to you.
I got a pair of Altec Lansing 120s some time ago and they're brill. Music is full and rounded not tinny at all. Cost around �20 about 9" high 3" wide.
http://www.amazon.co.uk/Altec-Lansing-120-Spea ker-System/dp/B00008KWWP/ref=sr_1_1?ie=UTF8&s= electronics&qid=1205676531&sr=8-1
The brands I hated at this price were Trust, Labtech and Logitech. These manufacturers couldn't make a decent pair of speakers below �50.