Mine was second gear as thats where all the slippery slidey stuff happens but bloody hell I found a roudabout (in my back garden) that was a fair size and 3rd gear got me like 270 degrees round it in style!
Overdrive 3rd. Coming onto a Motorway. Foot flat down through 3rd, hit 70, flick the switch and off we go without a gearchange all the way to...70, obviously.
5th. I can move off in it (just!), cruise at 800rpm and 30mph around town, then accelerate to about 120 before the car develops it's own highly interesting sense of direction!
Airfields are FUN.
1st is my pet hate gear as a) it's not particularly easy to get and b) it only goes to about 10/15mph...lot of noise, not much go.
2nd... on my Suzuki Bandit 1200 because it'll take you from a crawl to motorway points territory in very little time at all. It's either fun or frightening - haven't ever really been able to decide which so I complete the process regularly to try and make up my mind.