Here's a PM I sent to somebody a few months ago, my opinion on Hatfield (I live there, so I like to think my opinion counts):
...The bad points? Well the town centre is so crap. Unless you're keen on charity shops and takeaways. Hopefully they are doing it up though soon. Plus you can go to other surrounding towns, St Albans, Welwyn Garden City, etc. The shopping centre is ok (it's an outlet so dead cheap clothes) but it's nicknamed 'the gonnereha' haha. The cinema is also quite expensive I think (£6.50 peak times). A cheaper cinema and bowling can be found at Stevenage, 2 train stops away. However, that shopping centre could be a good place to get a job. Also there is little nightlife in Hatfield. You have CO2 (a nightclub), a few pubs and the student union, and that sums it up i guess... However you are close to St Albans which is significantly better in terms of going out, more restaurants, pubs, clubs, etc. Also you are quite close to London so that's ok.
The one good point I can think of is the bus service, which is quite good. It's called 'uno', run by the university and the buses are pink and purple. They go all over, St Albans, Watford, other places in Hertfordshire and even London, and are quite reliable and reasonably priced. Also, if you are sporty there's the hertfordshire sports village (its owned by the uni) and also Next Generation which is some really huge sports centre that was opened up about only a year ago, tons of sports facilities, it's dead good, so check it out. They are located near the Galleria (the shopping centre) in the Business Park.
There are tons of chinese students about who leave asda trolleys abot lol. Just to let you know. And Hatfield has some top notch chavs....