Here you have ahppy hour on Wednesday nights. You can drink for a very good price here. It is an Irish bar and drink the cheap beer and relax and then continue the night life..
Dress Code: Casual. Nothing special.
There seems to be a ton of Irish Pubs in Buenos Aires, and most of them seem to be grouped in one neighborhood -- near Retiro -- and Kilkenny seems to lead the pack. But I've never had a good experience at Kilkenny. It's always packed, too loud, can't get a table and the service is weak.
So, if you need a change from all that and you are in need of an Irish Pub and have a hankering for a good pint, might I suggest The Clover. Located between Monserrat and San Telmo, the Cover is not as crowded and there are a large variety of Ales and other beer. Try a Duvel; a top fermented 17 proof Ale. The music is not too loud and the staff very friendly and helpful.
Dress Code: none that I can tell