I really like the city itself. It isn't huge (I come from Manchester which is a fair bit bigger) but hasn't absolutely everything you need I reckon. Also I've seen a couple of people saying that they don't like the way the city looks but personally I love the mix of buildings; I think the jumble of old and new is lovely (but maybe that's the history geek in me!)
University Park has loads of open space and isn't too far from the country. We have an agricultural campus called Sutton Bonnington which might be interesting to you? One of my best friends is a Suffolk farmer and he seems more than content!
I'm not gonna lie, you don't have a huge amount of space, but then again halls are halls! Personally I loved my time in halls, especially cos I was staying on University Park. Halls really encourage you to get to know people you would never normally meet or get to know (my farmer friend being the perfect example of this!) The amount of space you have outside your room varies depending on which halls you are in and whether you decide to go catered/non-catered. I stayed in a catered hall which had a JCR with a TV with sky and a dvd player and a games room as well as a big dining room and sofa space on most floors. Some of the other halls have a library and other things. Unfortunately I haven't really spent any time in any other kinds of accommodation so I'm not much help there.
Personally I think the transport is pretty good. You can get from campus to the city for a pound, which isn't bad at all. There's the city train station and coach station and a train station in Beeston, which is a town near the west entrance of the campus.
Most of the freshers' events are in the city, although there is also a lot of stuff on campus. We also went into the city to explore/shop quite a bit. I think the reason I stayed in the bubble for so long is there IS a lot of stuff to try on campus (sports, societies, bars) and I was more concerned at that point with meeting people than exploring the city because I had 3 years for that! Also, while I am quite into the other side of uni life I did enjoy a lot of the week one events and stereotypical fresher's events at night. However there is sooo much choice, so if you're not into drinking and going out and stuff then don't worry!
I'm not gonna lie I'm definitely biased towards Nottingham and really can't see myself anywhere else, but then I never really could! As much as I'm selling Nottingham here please do consider where you think you will be happiest, because you're definitely going to do better if you feel content somewhere.
Hope all my ramblings have been useful