I went to university there and had a great time. It's very cheap, which helps when you are student of course! I'd concur with what others have posted - the area around the uni is nice and vibrant as is Cottingham (loads of halls of residence). Stay away from Bransholme and other areas in the east. I also didn't like the area around Anlaby Rd much if I remember rightly. I think west and north west are the best areas if memory serves me well. Beverley is lovely and there are quite a few fabulous villages not far away. Used to do lots of walking in North Yorks too, which is very accessible from Hull.
With regard to the smell, I don't remember fish being a problem but the odour from the dye factory was pretty bad when the wind was blowing in a certain direction. Not sure if that's still the case.
Hull has always suffered from being out on a limb but it does have decent rail links, good access to Yorkshire and the North East, the Humber Bridge links you up with Lincolnshire and the M62 means good road links to Manchester and Leeds. Of course it's also flat and so really excellent for cycling.
As someone else said, you can jump on the ferry. I went to Bruges on the overnight ferry when I was at uni and there were always good deals in the local paper. I moved as I was doing a postgrad in Sheffield and then moved to London for work. The work issue means I would be unlikely to move back, but I work in the media. You do need to consider the work aspect - what industries operate in Hull, but York, Lincoln and Leeds are all commutable.