Dave from Knoxville, this is why you have supercaller status. At 49, I assume that I will be a fullblown crank, uninterested in listening to anything but old-timey music. I heard a scientist recently talking about how our brains are hard-wired to prefer music we heard in our late teens, which might explain a lot.
Hip-hop is a huge, messy class of music that's hard to untangle; it's a bit like using the phrase "rock" to describe everything from Poison to Bruce Springsteen to Pearl Jam to Led Zeppelin and everywhere above and beyond. Jay-Z can go from being a deft lyricist in one song to then rhyming the phrase "trick ho" with...the phrase "gold-diggin' skanky ho" in the next song.
I'd suggest De La Soul's earlier stuff to cut your teeth on, definitely the Black Star album (back when Mos Def was good), and more Stones Throw stuff to throw a curveball. More and more, though, I find hip hop getting me more interested in finding out about the songs they're sampling.