Backlash 2007 for sure, as there are only 6 matches, but two fucking AWESOME matches in the Undertaker-Batista LMS , and the fatal four way between Cena-HBK-Orton-Edge. The PPV also features a great Benoit vs MVP bout, a great opening tag bout, and a few decent other matches.
No Mercy 2007 is possibly the greatest PPV ever if you're a fan of Trips, but if you aren't you should probably stay the fuck away
Cyber Sunday 2007 is recommended because it has an all-time classic for a main event in Taker-Batista, a near classic streetfight between Umaga and Hunter, a great stretcher match between Finlay and Rey, and a good WWE Championship bout between Shawn and Orton.
Watch Survivor Series 2007 just for the two main events. The Hell in a Cell match is fucking awesome, while the MOTN between HBK and Randy just so happens to be one of the best matches in Orton's career.