Land Rover Defender is widely regarded as peerless as an off road vehicle.
The 90 is great for a weekend toy, while the 110, has more load & passenger space. The only drawback (and it depends on your point of view) is that the defender lacks some creature comforts.
Alternatives can be the LR discovery or even an older Range rover.
All these are very capable, and can be extremly flexable. Most land rovers are also very suitable for the home mechanic - if thats your thing.
Other fun 4x4s are suzukis (SJ's, Vitaras) you can have lots of fun with them - but personally I prefer a land rover