As above, you will get all the answers from people who love their own vehicle, that may not mean it is the right one for you. Decide what weight you need it to tow, what else it will be used for, how important it is that it is relatively economical, then use the towing vehicles website as a starting point http://www.towinghorsetrailers.co.uk/towing_vehicles.htm It's a bit out of date, but if you then go to Auto Trader and search in your budget you can check what weights they are capable of in the stats for each one. I have had a Trooper (any still around will be getting far too long in the tooth, and a bit thirsty but cheap and good) a Nissan Terrano (again, not many good ones around and avoid the smaller SWB ones, not much room in the back) and now, because I can afford it, a SsangYong Rexton, (comfortable as a daily use car) all gave or giving good service.
I did consider Discoveries, but the ones in my budget were £550 p.a. in road tax!!! I also considered VW Touareg and Tiguan but the local dealer was less than helpful - all of those towed the 2.5 - 3 tonnes I was looking for.
My advice would be buy the 4x4 with the highest towing weight you can afford. I had a VW Tiguan to tow a 511, it was adequate for towing trailer + 1 pony but didn't feel great up hills etc. Upgraded to VW Toureg and it is so much better.
Also would recommend an automatic makes towing much smoother. Have always driven a manual and didn't want auto (mostly because my big sister kept telling me to get one) but now love it!
yep: personally I got an 06 plate Disco a few months ago and I love it- tows like a dream, and 3.5 tonne capacity, so barely feel the trailer. Not bad off road when needed either. But importantly for me it is a relatively comfy day to day car. road tax very expensive, not very efficient, but 4x4 that can tow 3.5 are not ever! I don't travel very many miles day to day so not a big problem for me. We also have a second car (my husbands) that is better for long journeys not towing.