I've been holding off commenting on this post, since I really wanted Olaf jungle to work, but at the moment, he's pretty weak since he has very few options as far as engaging (and is not as much of a pure tank as many other junglers). I still want to say he's strong despite being suboptimal as far as picks go, but he does have heavy weaknesses in the current, mobility heavy meta. Speaking of the meta, J4 and Maokai are probably the top tanky supports, J4 more on the offensive side and Maokai on the defensive side. Amumu is a good pick as well.
One pick that I haven't seen mentioned yet though is Nunu; he's somewhat situational and very unique as far as junglers go, but he gets very tanky with very few items, has pretty much unparalleled objective control (since his Consume is basically a second smite), really good synergy with many of the hypercarry ADCs that are popular now because of his Blood Boil (and also counters a lot of the hypercarries since his Ice Blast reduces attack speed). His ult is great for teamfights, as an engage or disengage, and he has a lot of jungle control; his job is really to provide great utility to his team through vision and also denying (aka annoying the living hell out of) the other jungler by stealing big monsters or buffs with his consume+smite, following them around and smacking them with snowballs, then running away before they can retaliate, etc. I'd say he might be harder to play in solo-q since he needs a team that actually knows what Nunu is doing and supposed to be doing, but he can be a very powerful pick.
I also want to mention that there's more variation to champions than full-tank and squishy-carry. I'm sure you understand this, but from the sound of your first sentence, it seems like you making a very hard distinction. A full tank Amumu with nothing more than a Sunfire Cape and Haunting Guise in the way of damage still can wreak havok on the enemy carries. A traditionally squishy jungler like Evelynn still builds tank after Elder Lizard and maybe a Hexdrinker or something, and mid to late game really transitions into being a good off-tank. Most junglers are like this actually; offensive jungle item + a lesser damage item, then build full tank.