Old Franchises That Can Still Be Revived
Kurt Russell has said that out of all the characters he has played in his career, Snake Plissken is his favourite, and it's easy to see why. He's a sarcastic, gritty badass who delivers one-liners and kills without compunction. It's a brilliant role, and Russell sunk his teeth into it.
It took 16 years for Escape from New York to get a sequel, Escape from LA. It was intended to lead to another sequel, Escape from Earth, but the film's box office was dismal, and plans were dead in the water.
Here we are 16 years after Escape from LA, and another Plissken adventure seems feasible if someone is willing to fund it. And that's the problem, really; it's hard to get proper funding for an R-rated action movie. Plus, John Carpenter isn't really working much anymore, and it's hard to imagine Carpenter concerning himself with another Plissken adventure. Russell would do it in a heartbeat, though.
Chances It'll Happen? 3/10

This is a strange one to include on this list, as it looks like a third Conan movie with Arnold Schwarzenegger is happening, but it hasn't happened yet and it's still in the rumoured stages, so I'm just championing the idea.
After the failure of the 2011 Conan reboot, it would be perfect to bring back Arnie and give him one last Conan adventure. He's older, sure, but he's in AMAZING shape. He's still a buff tank who could rip a man's arm off with his bare hands, and it'd be quite something to see the aged Arnie kicking ass with a fucking huge sword.
This needs to happen. And it needs to be R. And John Milius needs to be involved.
Chances It'll Happen? 7/10
UPDATE: There's talks it will shoot this year (2015)

I know it probably seems like an idiotic idea to bring back Jim Carrey as Ace Ventura, but if it was done right...it'd be awesome.
Carrey is showing a willingness to get back to his roots now. After a few years of taking it easy, he's now doing the sequel to Dumb & Dumber, even though the original movie was already sullied by a prequel without the original cast. Ace Ventura was sullied by a woeful spinoff without Carrey, so why can't they make a new Ace Ventura adventure with Carrey?
I'd just like to see more of this type of silliness. Carrey has still got it.
Chances It'll Happen? 4/10

Yes, I know this movie spawned two direct-to-video sequels and an animated spinoff, but Starship Troopers deserves a theatrical sequel supported by a solid budget and the kind of ingenuity that Paul Verhoeven can provide.
It's probably too late at this stage, but c'mon, what the fuck are Casper van Dien and Denise Richards doing these days? Verhoeven isn't doing much, either. With the right script, a franchise revival could be awesome.
Chances It'll Happen? 2/10

It's the perfect time to bring back the Lethal Weapon series for just one final hurrah. Mel Gibson has recovered after his various public humiliations and is back in films (Machete Kills and Expendables 3), Shane Black is suddenly a major player in Hollywood, Richard Donner could use a return to form, and Danny Glover still isn't too old for this shit.
Whether or not you'd like to see the forever-rumoured Lethal Weapon 5 falls down to personal choice, but I'd like to see what Riggs and Murtaugh are doing in their latter years. Both would likely be retired by this stage in their lives, but something could pull them back into action.
Lethal Weapon 4 was a very underwhelming way to close out the franchise. Entertaining, sure, but not a patch on the first film. Shane Black could write a magnificent final film and send off the characters in a proper fashion.
Chances It'll Happen? 5/10

48 Hrs. only spawned one sequel, and it wasn't good at all. It felt perfunctory, to be honest, as if everyone was just doing it for the sake of a payday.
Imagine what could happen if Eddie Murphy, Nick Nolte and Walter Hill actually put their heart into another sequel... They could all use another hit, for sure.
Chances It'll Happen? 3/10

Talks of Alien 5 have persisted for a few years, but nothing seems to be coming of it. Ridley Scott is too interested in his Prometheus series now, though, and nobody seems to want to do it anymore.
It'd be nice to see Ripley again, but that'd probably be stupid. I'd just like to see another sci-fi film featuring the xenomorphs.
Chances It'll Happen? 4/10
UPDATE: Well blow me, it's happening, with Neill Blomkamp masterminding it. Now, if more of the ideas on this list can be used...

Here are some old franchises that should be brought back from the dead, and could still be done so successfully.
Suggestions are welcome. Patronising comments will be replied to with the same amount of patronisation ;)