First, download my intro to mashups playlist. 70MB, 12 songs.
Half the fun of a mash-up is recognizing the songs being juxtaposed, so this list is biased to songs I know and hope you'll know too.
1. Hank Handy / "Beatles mashup" : 03:34
2. The Beatles / The Monkees / "Paperback believer" : 02:25
3. Nine Inch Nails vs The Beatles / "Come Closer Together" : 04:18 [explicit]
4. Go Home Productions / "Crazy little fool" : 02:34
5. 50 Cent Vs. Bee Gees / "It's your birthday vs Stayin' Alive" : 06:49
6. Go Home Productions / "Velvet Sugar" : 03:22
7. Go Home Productions / "Girl Wants (to say goodbye to) Rock And Roll" : 4:20
8. Dean Gray / "Dr. Who on Holiday" / American Edit : 04:57
9. Dean Gray / "The Bad Homecoming (Waiting)" / American Edit : 03:25
10. Dean Gray / "Whatsername (Susanna Hoffs)" / American Edit : 03:28
11. Everything But The Girl vs ATB / "9pm And Missing [Bootleg]" : 05:07
12. Armin van Buuren vs Coldplay / "Fix You vs Zocalo (Chupinolas bootleg)" / Shivers : 08:20
Running time: 44:57
We open with four Beatles songs. The first track is a tour de force mash-up of dozens of Beatles tracks. Hank Handy uses ProTools to pitch-shift, time-shift, and edit into a frantic mess. This one is fun for playing the recognition game.
The second track, by Mark Vidler, aka Go Home Productions, is a much more typical mash-up, just two songs. The weakness is that it makes its point in the first 30 seconds. The next two use editing more heavily to blend the two songs into something new. (I don't know who did the NIN/Beatles mash, but it wasn't Vidler.)
Track 5, "Stayin' Alive" vs "It's your birthday", never fails to kill me.
Two more from GHP, slick and clever. No new ideas there, however.
With track 8, we get into some truly tasty mashes. Dean Gray's American Edit is a mash-up of Green Day's American Idiot album in its entirety. Many songs make brief appearances, to make political points as well as musical ones. These aren't as frenetic as the Hank Handy, but they're way more complex than Mark Vidler's. Dr Who samples, U2, seventies standards, the Bangles' "Manic Monday", and others appear over the spines of the Green Day songs. The wikipedia article has a partial list of samples. The entire album is easily available for download via your BitTorrent client.
We close with a personal favorite: a great trance anthem against emo!rock. This one is very simple. It's "Zocalo", sped up just a trifle. As it builds to its climax, "Fix you" bursts in and sends it over the top. The genius here is in the unnamed DJ who heard the two and realized the progressions are the same.