I don't so much prefer one "style" over the other - per se (rather enjoy all...as Trent suggested), as much as I typically don't like the recorded "sound" of the newest stuff out there. The older things...even from the 70's and backwards...had a much more raw, vibrant sound to it. Much of what I've heard today sounds almost sterile...perfect...and in effect, is almost lifeless..or perhaps robotic.
Maybe it's in the recording techniques used. Maybe I just like the way some engineers record/master over others. One of the relatively newer things I've touted is Michel Camilo's "One More Once" big band cd. Maybe the way's it's recorded is one of the reasons I suppose I like it. (though, great emotional playing - superb arrangements surely help!) Nothing sterile about "that" recording. Especially the tune, "Not Yet". Damn, that's ballsy.
The great older tunes that Chuck mentions will always be "great". Good is good...forever. I really enjoy turning on my kids - little by little - to some of the older stuff. It is very cool to see them appreciate great music, no matter the era. I came home one day to see my son's computer had - as the wallpaper - a pic of Buddy Rich.
There may be hope yet, boys and girls. ha.