I like bolts that lock when the safety is on. Hunted with 700's years back and had the bolt lift several times. I have a couple of dandy 700's that shoot great, but I rarely take them in the field these days.
My favorite safety is low on the tang like the older A-bolts or X bolt. I do a lot of upland hunting with O/U's; thus, a tang safety is as familiar and quick as it gets for me. A close second for safety position would be to the side of the bolt as it is in the Tikkas and 700's.
I dislike 3 way safeties that swing around the back of the bolt shroud. Most of it is certainly unfamiliarity on my part, but I find the move from all the way on to all the way off long and cumbersome in comparison to other safeties. I know it's going to draw ire from model 70 fans, but they seem meant more to appease class action attorneys, not gun enthusiasts.
A thought on safeties that allow loading and unloading on safe: Not saying I mind a bolt unlock device like the S20 or X bolts have, it's just that it bothers me on several levels that we're willing to accept and acknowledge such a level of unsafe gun handling that we have to build guns to accommodate it. I get it that accidents happen and it's a tragedy that could've been avoided, but, to me, the blame needs to go on unsafe gun handling, not the safety. Barrels should never be pointed in a direction that could cause trouble, especially when there's a live round in the chamber. Even on the best safeties, there's just not much preventing the firing pin from striking the primer.