I reckon 5 inch speakers can carry you very far for the money and without annoying neighbours also. When it comes to mark and model, you have a lot of options as well as opinions. But All you can do is pick a few tunes that you feel have good sound qualities and that you've listened to many many times. Then go to your local music gear retailer and ask if you can test them with your cd, or iPod or whatever. The choice is in the end yours. Don't buy what you hear from based on what you read.
But one mark that hasn't been introduced here yet (i think) are ESI nEar models, they come in 5 and 8 inch varietes and are very cheap, the smaller is 165€ per pair.