What kind of music/atmosphere do u like?...the best ones are Level(BellaTerra Mall), Sahara(right in front of the Metro Bus station), Dubai(Plaza Zona Rosa), Moma (Plaza Internacional), Francifol(Calle del sol), Tribecca(can't remember the name of the street)...a nice bar would be "Alambique" (Jardines Metropolitanos).
Yes, Ahi-Bar is your best bet on Sunday night if you don't mind suffering hearing all those people who can't sing. It will be hard to find a free seat.