Well, if it's post Pixies, I think you'll be well past the danger zone for after-match-aggro, particularly on that short stretch of Argyle Street.
This happens to be my manor, and can add a vote for the Ben Nevis. In fact, you're spoiled for choice round this way.
Just beyond (or on the way to Ben Nevis, depending on which pedestrian route you choose), is a bar called the 78, which should, if it's a chilly eve, have a real fire going. One of these goes really well with a pint of their cask ale.
Across from Ben Nevis is the Ivy, which'll have a younger crowd, and no doubt a fair few fellow gig-goers if you wanna squeeze the most atmosphere out of the night.
If you want something of a pleasant surprise, try The Rogue on Old Dumbarton Rd. I've taken a few out-of-towners there, and they have really enjoyed it. You'll have to walk a block up towards the BP garage, passing the Goat and Firebird on the way, but it's got a good, friendly atmosphere, and an eclectic playlist and open to negotiation on what's played.
Owner comes from Halifax, the home of the Mighty Orange Bikes.
Enjoy the gig. Let us know what you thought of whrever you get to.