Those who have been fortunate enough to do at least one trip will all have that surreal experience of walking out of the train station to find sometimes frankly bizarre sights involving blues, alcohol, midget prostitutes and other continental delights. Here are a couple of mine:
Lokeren - got off the train about 30 mins before kick off, walked out of the main doors of the train station and saw utter carnage. The place was like the Alderley Edge of Belgium the day before the game, but on the day of the game as we walked out of the train station, there were two little police tanks on the main road with blues swinging from the guns singing blue moon and the town looked like a war zone. There hadn't been any trouble, but imagine 5000 blues descending on a nice little village in the middle of nowhere, and that was Lokeren
the day before the game in Brussels, someone climbed up this

Funniest one from that trip was my mate who flew to Amsterdam, had a proper heavy night then got on the train to Brussels. He rang me when he arrived at about 2pm asking which bar we were in. Gave him directions, only for him to ring me 5 minutes later to tell me he had just realised he slept through to Paris
Groclin - the story of the upturned portaloo in the ground is now the stuff of legends, can't even describe how fucking minging it was though. It also spawned the additional story of armed police entering the plane at Manchester Airport.
I'll post up a few others when I have a bit more time