There are a dozen or so bars in Argentiere, the main place for most being The Office (+33 (0) 450 54 15 46; the-office-bar.eu) which has become something of a resort institution over the years and always has half-a-dozen good draught beers on tap.
The Stone Bar (33 (0) 450 54 13 17; chamonix24.com/bars/stonebar.htm) is another popular venue, it has made a play for being more of an après ski wine bar venue. Both are open to 2am and run lots of drinks and food specials through the week.
You could also try The Rusticana (+33 (0) 450 55 88 28)(or just ‘The Rusty’ to its friends) and the more French Rencard (+33 (0) 450 54 14 02) – both pleasant enough. The Savoy Bar is located in one of the oldest buildings in the resort and serves microbrews from the local Microbrewery in Chamonix.
Of course for a full on nightlife you’ll need to pop down the road to Chamonix with its big choice of bars and late night venues (see separate entry).