Hmmm...like Chaz, I also get attatched to strange things for sentimental reasons.
My favourite stations are Manchester Piccadilly, Derby, Doncaster, London Euston, Birmingham New Street, London Waterloo and Hastings. There's probably more that I can't think of offhand.
Manchester Piccadilly: Has a nice friendly atmosphere to it. Large station, but still very compact and easy to navigate. Good selection of shops in the station, but not in the way like St Pancras.
Derby: I used to change at Derby alot when I first got into trains a few years ago and always got excited about the RTC. I used to spend hours there at night waiting for my bus home, so I've grown to love it in a weird way.
Doncaster: Decent selection of freight passing through.
London Euston: Not particularly a nice station in the platform area, but the concourse has been recently improved with more seating. Good selection of places to eat aswell. Oh, and the best part about Euston, is waiting for the next Pendo platform to appear on the departure boards, and then as soon as it does, racing with the entire station to be first onto the train and get a seat.
Birmingham New Street: Easy to navigate, especially with the amount of platforms. Directly linked to several shopping centres.
London Waterloo: Again, really easy to navigate. Although the new ticket barriers are quite an annoyance for anyone unable to get through the automatic gates! Subway at rush hours provides a quick way to get onto the tube without having to push through people on the concourse. Also a link straight to Waterloo East for Southeast Trains services.
Hastings: Just a plain fantastic looking station from the outside. Looks absolutely stunning!