Madrid Restaurant Recommendations?

Hey Folks,

I'll be in Madrid next month (Friday - Sunday), and am looking for some restaurant recommendations. I'll be alone (and I'm totally comfortable with that), so I don't want any place too austere or formal. Interested in traditional Spanish spots, or hip/trendy, as long as the food is excellent.
Also, would love to have some suggestions about which bars/lounges I should check out after dinner.

Thank you!

Cava Baja st
Los Huevos de Lucio
Ensalada de perdiz(15,5 eur) & Cava Imperial Gramona (18 eur)
Simply the best tavern in Madrid and one of its most unforgetable combinations.
Get there early, before 9:30 pm
Don´t mistake it with Lucio which is in front of this tavern.

Andrés