I use an older DeWalt one, mainly because it matches the rest of my cordless tools, but also because its small bodied, so can get in tighter spaces.
It's claimed to be something like 185Nm, but tests with my torque wrench put in nearer 150Nm. Most of the others I've tried that claim 10,000,000Nm achieve about the same, or less.
Obviously, I can't recommend mine as its no longer made, but I'd say you want:
A genuine >150Nm - this may not be enough for everything, so you may have to crack some bolts with a ratchet first, but enough for most.
A small body - to get in tighter areas
A variable trigger - essential for doing stuff back up without cross threading or over tightening.
Most I've seen claim about 250nm, something smaller as you say to get into tighter areas would be handy, but that would compromise on torque, although I'm really just looking for something to run bolts in and out, I prefer tightening most bolts to specified torque, so torque rating not so important, but hopefully the best part of 150nm to remove most nuts and bolts.
Thanks all for suggestions so far.