Having just returned from a trip to York, I think the place is teeming with activity, compared to Carlisle.

A stock list -

GNER: 43s and 92s.
Virgin: Voyagers.
Northern Rail: 142s, 144s, 153s, 156s and 158s.
Transpennine Express: 158s.
Central Trains: 158s.
Freightliner: Mainly 66s, but others, too.
EWS: Same as Freightliner.

There are lots of good facilities nearby, and it's quite common to see a heritage steam or diesel loco.

To get numbers from Freightliner-liveried 66s on the avoiding line you will need binoculars, no matter where you are at the Doncaster end of the station. No such problems with EWS and their handily huge numbers.

The NRM is now a couple of minutes walk since the extension of the footbridge. The station has a Burger King, WH Smith, pub, and numerous Traveller's Rest-type outlets. Recently there have been a number of Meridians and 170s (the former for testing; the latter for reasons I know not), but the mainstay is still classes 43, 91, 144, 150, 153, 155, 156, 158, 220 and 221 (especially 158s on TPX duty). York obviously also attracts a lot of steam and classic diesel traction passing through on railtours.

The station sees numourous GNER 91/HST sets and Northern Spirit units plus twice hourly Voyagers in each direction.
Most freight uses the avoiding lines to the south of the station but is easily visible from the south end of the platforms. Facilities are good on the station and the city centre is only minutes away. Car parking in York is difficult and expensive but a good value park-and-ride bus operates from 4 locations around the city all day.
The railway museum is about 5 - 10 mins walk away.