TU 154 is still in regular use by Belavia out of Minsk, sometimes in Warsaw. They are also an operator of the CRJ, but then so are Lufthansa Regional and SAS too.

Belarus has a few domestic airlines which fly older Soviet aircraft but the ability to buy tickets or even see when routes area operating is pretty difficult.

Transaero also operate the TU 214, although not sure if this flies in to Western European cities.

Luffty 747-800?

You didn't state old and rare ;)

There is an Estonian airline that operates some shady aircraft models. Don't know any names right now, but worth looking into maybe?

I had the misfortune to go on Blue1's B717 this summer. It was noisy and crammed, and the extra super duper mega first class ticket was SO not worth it. I was seated in the very front of the plane, butting knees with the FAs on start and landing. Still the noise levels were horrendous - I can't imagine how awful it must have been further back! Crew was very nice though. One of the pilots greeted me almost as an old friend - I was extremely surprised by that.

Ruby Star?

I saw an Aer Lingus B757 at DUB a few months ago that was doing the Dublin to Toronto route, it even had an Irish EI- registration.


SHJ

Managed to get a ride on an Aeroflot IL-96 in 2013 before they were taken out of service last year. Magnificent. Not so lucky when I tried to go on an AN-24 from Tromso-Murmansk, as the flights were suspended last autumn due to regulatory hiccups in Norway. Flights from Moscow to Saratov and Izhevsk are still possible on YAK-42s, though they are slowly being replaced with western types.