In Numerical order only with no preference to order intended and going over Ten in regards to Series, so whilst some may have had one of the movies riffed, I'm wanting more from those series:
1) Star Wars
Obi Wan Kenobi: And these BLAST POINTS!
Too accurate for Sand People. Only Imperial Stormtroopers are so precise.
Uhh...pardon o_0' No wonder Uncle Owen called him a Crazy Old Man.
2) Flash Gordon
Dale: Flash! Flash I love you but we only have 14 Hours to save the earth!
Don't you just hate it when they slap a time limit on the most difficult part of the game?
3) Lord of The Rings
Aragorn: But we can give Frodo this chance if we keep Sauron's eye fixed upon us. Keep him blind to all else that moves.
Legolas: A diversion.
All Together Now... DUH!
4) A Film from the 'Arnie' Genre
Place Quotable Arnie line here.
And place Riff for quotable Arnie line here.
5) The Karate Kid
Get Ready for Maximum Mayhem as Marvel Comics and Happy Days team up to face one of the most horrifying things known to man... A LUKE SKYWALKER CONVENTION!
Superman: Listen, what do you hear?
Lois Lane: I don't hear anything.
Superman: I hear everything. You wrote that the world doesn't need a savior, but every day I hear people crying for one.
And because I got so fed up with your whining, I left for 5 years!
Doctor: If you fight again, you could die.
Rocky Jr: GET HIM DAD! HE TOOK MY ROOM!
Yeah...way to keep things in perspective kid.
Greetings! I am Juan Sanchez Vilalobos Ramirez.
It's short for Sean Connery.
9) Metal Gear Solid
Yes, it's a video game series, but given the fact that the games have a cutscene viewer or if you have Metal Gear Solid 3: Subsistence, which comes with a DVD Movie using cutscenes from the game, it can easily be riffed, and the games are just filled with Riffable moments. Take for instance this classic moment in the very first Metal Gear Solid.
Snake: A SURVEILLANCE CAMERA!!!!
A SURVEILLANCE CAMERA IN A NUCLEAR DISPOSAL FACILITY?! NO FUCKING WAY!!!
10) The Transformers The Movie
Ultra Magnus: But Prime, I'm just a soldier. I'm not worthy.
Optimus Prime: Nor was I...
Untill I gave the guy 20 bucks.