The only vehicle I would consider instead of my 110 would be a G-Wagon but they're just too expensive. I've done a fair bit of trekking in 110s and love the load space and go-anywhere capability (yes, I know others can do it as well, but I like the 110). In deserts, dried up river beds and over rocky mountain passes a trailer is a pain and a liability in my opinion so you end up doing treks that you could do in a normal car - with a vehicle with a decent load capacity a trailer isn't really necessary.
I recommend the guru Tom Shepherd's books - "Vehicle-dependent Expedition Guide" and "Quiet for a Tuesday" where he discusses at length the pro's and con's of various vehicles. Tom went from Land Rover to G-Wagon; I'll leave him to explain why
I’d add a 70 Series Land Cruiser (and maybe a Pinzgauer - but have no first hand experience of them) to that list but in reality any well sorted pre-electronic era European or Japanese 4x4 will take you most places you could want to go - even those that the locals get to in their battered Hiaces and ancient Mercs and Peugeots.
Simple, lightweight cars like Renault 4s, Citroen 2CVs and Fiat Pandas are surprisingly good on the desert pistes and these guys had some pretty cool adventures in an old Type 2 VW.
http://www.vwvagabonds.com/
I was half seriously thinking of taking my 1978 VW Westfalia Campervan to Africa before selling it and buying a 300 Tdi 110 instead.
I love the idea of a VW Synchro but having met a very frustrated Austrian lad stranded in Nairobi unable to source (even from Europe) some basic parts to get him back on the road and having a mate here experiencing similar problems, I would be wary of taking one somewhere too remote.
Sadly too many people get hung up, not just on vehicle choice but on the kit undreamt of in the golden era of independent vehicle exploration in the 1950s, 60s and 70s. It really annoys me that the sharks that run 4x4 expedition preparation companies who have stalls at Land Rover and Expedition Shows try to convince people that they cannot go on a two week tag along trip to Spain or Morocco without spending £1000s on nice to have but certainly not essential modifications and kit. A spirit of adventure is IMHO more important than vehicle choice or kit.
Tom Shepherd may be the guru but Gunther Holtorf who has been roaming the globe in his ancient G Wagen for decades now is my idol and the poster boy for the get a decent vehicle some basic kit and then JFDI!
http://www.bbc.co.uk/news/av/magazine-29505145/gunther-holtorf-shows-off-otto-his-mercedes-g-wagen
IIRC, Tom Shepherd fell out with LR when they ignored his suggestion that Defenders should have front and rear difflocks (an excellent idea) rather than electronic traction control. He bought a modern G Wagen and them Mercedes had to fly technicians out to the Sahara to fix an electrical problem that had left him stranded!
