Not too many legitimate responses here, so I'll step up to the challenge...
Mainstream rap is garbage, but there is some fantastic hip-hop that does not get the recognition that it deserves. Real music, not brainless drivel.
A few of the best:
-The Roots- Water
A mind-blowing live show. I've seen them twice and want to see them many many more times. This song is for one, brilliantly written, talking about resisting the temptations of **** use in the music industry. Two, it has one of the best bass lines in any song ever.
-Atmosphere- Always Coming Back Home to You
It's criminal that Atmosphere doesn't get a bigger recognition. This Minneapolis M.C. is one of the smartest, funniest, and most personal artists currently active. This is his best serious song.
-Atmosphere- National ********
I've got to include the less serious stuff by him as well. This track is funny as hell, talking about ********* infamy.
-Jurassic 5 - Sum of Us
Chali 2na's deep bass is one of the most identifiable and memorable voices in hip-hop.
-KRS-One - Step Into a World
"I'm not saying I'm number one, uh, sorry I lied. I'm number one, two, three, four, and five." One of dozens of awesome lines in this song.
-A Tribe Called Quest - Like it Like That
Super chill hip-hop that just rolls off the tongue. Cool as hell. My ears can't get enough.
-Afroman - Crazy Rap
Funny, filthy song. Big guilty pleasure of mine. "I met this woman from Japan, never made love with an African, I fucked her once, I fucked her twice, I ate that pussy like shrimp fried rice."