For the varied music styles of music you said you liked, here's the general speaker progression from entry level to ultimate:
JBL L100
Klipsch Cornwall
Altec Model 19
Don't be afraid of EQ's either. I know they get poo-poo'd a lot here, but they do serve a purpose if used properly. Most people make all the sliders into a 'smile' shape, but that's not really how they were intended to be used. If you don't have a spectrum anayzer on the EQ, here's what I did for my L100's. I pulled 7600hz down about 6dbs on my L100's. Made them less 'forward' sounding. If you get too much boom from room placement, cut the 64hz also. Using an EQ to 'cut' is a generally accepted method to correct things. When you 'boost', you change things. May sound like a matter of semantics, but it's all in how you view things.
And as always, your mileage may vary. I have a Marantz 250m powr amp, and that one works well with my JBL L100's and people say it is also a perfect match for the Klipsch Cornwalls. As others have mentioned time and time again in other posts, the entire chain really comes into play. And you can only figure that out by trial and error, and sometimes just getting lucky.