I don't claim that this list is in any way complete for Dallas. I do not go to karaoke every night either. But I do go out often, and when I'm picking then the places I'm likely to pick on a given night are likely to be here. If I go somewhere and like it then I'll add it.

SundaySherlocks on Central with DJ Hefty 9-1
MondayWest End Pub 8:30-1
TuesdayThe Cavern Upstairs bar 10-2
Uptown Bar & Grill 10-1
Lone Star Cafe 8:30-1
WednesdayThe Corner Bar 10-1
San Francisco Rose 10-2
Lota's Goat 9-2
ThursdaySharky's 9:30-1:30
Knox Street Pub 9-1
The Libertine 11-2
Lone Star Cafe 8:30-1
FridayBritish Rose Pub 9-1:30
Best Days8-1:30
SaturdayBritish Rose Pub 9-1:30
Sharky's 9:30-1:30