S120s - probably the best balanced passive speaker that B&O made. Plenty of bass. Only problem is that the bass cones suffer from foam rot but this is quite easy to repair. Should be cheap - almost nothing if foam rot not repaired.
S45-2 - smaller and so not so much bass as the S120. Again a very accurate speaker and good top end particularly. No foam rot as rubber surrounds - lots around. get ones with stands if possible. Nicer wood than the S120s.
RL60.2 - much more modern. They can be placed in a number of positions but I think if on the floor, they are bass heavy. You need the stands. Can need new capacitors but these are very cheap and easy to replace. I don't think they sound as good as the S45 and s120 but speakers are a matter of taste. If you are playing rock, these will be more to your taste.
CX100s - incredible for their size. Pleasant to listen to but seriously lacking bass. You need a Cona sub-woofer if you plan to use them as main room speakers. Not really Hi-Fi but very pleasant to listen to - I use a pair every day!