Basically, monitors are tools. To me, just listening and/ or using them to mix with, are two completely different things.
When mixing, I need speakers that I can trust will give me an accurate representation of what the recorded music, sounds like.
For casual, or even active listening, I want speakers that make the music sound good. I find typical monitor/ mixing speakers too revealing for general listening.
Anybody, who is not a speakers sales person, will tell you to buy what sounds best to you. Really, you actually have to get out and listen to some speakers. Then add-in your budget and the choices will be narrowed. Bring some of your favorite CD's along. If the music you like, sounds good on a pair of speakers then you may have found your listening speakers. If you hear things that you never heard before in your favorite music, and especially if you hear glitches, you may have found your mixing speakers.
FWIW, I don't think good monitor/ mixing speakers have to cost a ton of money. If you think of them as tools, it's easier to narrow the choices, especially when matched against your budget.