Prefer single lock on point as I tend to have my hands right on the end of the grips.
I was about to jump in with my nominated favorites, but both have double clamps.
Don't Specialized do one sided clamps for shovel-handed handlebar helmspeople (apologies for the alliteration, I got carried away).
ESI Chunky, not lock on but don't move
Esi +1
Liking my Lizard Skins Northshores and have ridden ODI Rogues in the past, which are also great, but again both are double ring lock ons.
Race face good n evil. a bugger to get off though.
Lizardskin North Shores for me.
Esi chunky user here once fitted they don't move much more comfy than any lock on or normal grip I've used before
Chromag Squarewave XL
Double lock on but grip shape means you don't want to hold the end. Best I've found for big hands. Esi chunky were comfy but a bit small.
http://www.chromagbikes.com/grips/squarewave-xl