Part of the reasons Aimpoints are so rugged is in fact due to its tube shape.
What's so bad about canting an Aimpoint?
Of the small "tubeless" type sights, the Trijicon RMR is going to be the most rugged option, hands down. Of course, it's also among the most expensive, perhaps for that reason.
Personally, I don't care for the tubeless sights, especially the ones with auto-regulating brightness. *I* want to decide how bright the dot needs to be, thanks; don't need the sight to do my thinking for me (I had a Tasco Optima back in the day, so I speak from experience). On some sights of this type, there's also the potential for water or dirt/debris to occlude the laser emitter window. If that happens, it renders the sight unusable, and can be a PITA to clean out. I haven't spent much time with an RMR, so don't know if that's a possibility with that particular model.
Personally, I'd opt for an Aimpoint Micro (or if on a budget, a Primary Arms or FM micro dot) for the application you mentioned.
I think my mind has been changed. Aimpoint micro is what it'll be.
I'm looking for a red dot to put on my next rifle. It can't be anything in a tube. I was looking at the Burris Fastfire and the C-More sites.
Which is more rugged? I'd like to be able to drop it and now worry. This will probibly end up on a .223 rifle.
Any other options out there?