According to the latest Darkshade Vote, the coolest form of Time Travel is to hop in Doctor Who's TARDIS, followed by the famous Delorian from Back to the Future.

Quoted Text

Coolest form of Time Travel
TARDIS: 55.56%
Delorian: 27.78%
Starship slingshot around a sun: 5.56%
Staring intently at an old watch: 5.56%
Closing your eyes and concentrating with your mutant power: 5.56%
Quantum Leap Accelerator: 0.00%
Big Spinny Disc behind a chair with levers: 0.00%
Subspace anomoly: 0.00%

Total Votes: 18

For anyone who might not recognize each of the time travel options, here's where they came from (including a picture, cuz I was procrastinating)

First off, one of the least favourite options, the subspace or temporal anomaly.  Here is a picture of the Enterprise "C" coming through such an anomaly in "Yesterday's Enterprise" from Star Trek: The Next Generation.

Also at the bottoms was "The Time Machine" by H.G. Wells.

Tied in last place was the Quantum Leap Accelerator from the TV Series Quantum Leap.

Actually receiving a vote was Hiro's time travel power from the tv series Heroes.  He squeezes his eyes shut and concentrates on where and when he wants to go.

Tied for second last place was a rather obscure reference to an old Christopher Reeve movie where he falls in love with someone who lived in the past (Jane Seymour) and he uses an old watch to "will" himself back in time to meet her.
One of the interesting paradoxes with this story is where did the original watch come from?  He ends up with it in the future, goes back in the past and gives it to Seymour, which leads to him getting it again in the future.  Lather, rinse, repeat.

A trick used too often in Star Trek movies and shows is the notion that if you accelerate a Starship towards the sun, and then break away at the last moment, you'll be hurled backwards or forwards through time.

Qwantz.com had a great dino comic about this, regarding why they don't just go back in time to change the outcome of any unpleasant event, but I can't seem to find it.

In second place is the vehicle from one of my favourite movie trilogies, The Delorian.  A really worthless car, but equipped with a Flux Capacitor and 1.21 Jiggawatts of power, can travel to any time once it reaches 88 mph.

And the Number One form of time travel, Doctor Who's TARDIS.  It's all in capitals because it's an acronym for "Time And Relative Dimension In Space".  It's got a broken chameleon circuit, which is why it's always shaped like a Police Box, and apparently takes 6 people to pilot, which is why The Doctor often has trouble controlling it.

Coincidentally, David Tennant has recently announced that he will be leaving the role of the Doctor after this year (2009).

Sadly, we forgot a couple very important methods of time travel!  Bill and Ted's excellent phone booth!  Also missed was the technique in Stargate of opening a wormhole through a solar flare.

I have to admit, there are some pretty cool methods of time-travel here (the Delorean and TARDIS are classic), but in a world where I actually got to choose one for myself, I would take the method that didn't require me to rely on a mechanical device, or the necessity of getting to a certain location.  I can squeeze my eyes shut anywhere, and my blinking mechanism isn't likely to malfunction (and it doesn't require either lightning or plutonium).