I have mine set to 4 minutes because I do a lot of ebook reading so, if I'm reading in public and get distracted mid-page by something, 4 minutes is usually long enough so that I can get back to reading and get to the next page-turn before the autolock kicks in.
I could probably get away with 2 minutes in the winter but, in the city in the summer time, I find that there is more to distract me so the higher timeout is frequently useful .
5 mins cuz if I'm playing a game or something of the sorts and lace it down to get abdrnk or something I don't want it to upset it by having to unlock my phone.
Five minutes. I used to manually lock it, but this turned problematic when I browsed right before bed. I'd fall asleep and the battery would drain; I'd have no alarm clock for work.