We recommend the The Wheatsheaf around the corner, which does everything a traditional English pub should, including great beer.
A glass of plonk in Dean Street Townhouse, a margarita in El Camion (Brewer Street) or some late night jazz at Ain't Nothin But… Make a great first impression by meeting at the Charlotte Street Hotel, where you can sit on a cozy sofa in the back room and get to know each other in peace (the front dining area near the street gets a little noisy).
For the sake of your wallet (and to find somewhere a bit livelier), you may want to head over the road next to cocktail bar Bourne & Hollingsworth (Rathbone Place).
From there head North towards Old Street and, if you can, stop for a drink in Nightjar (City Road), the wildly popular bar where the cocktail list is so extensive it's divided into historical eras.
From there, head east to Callooh Callay Bar (Rivington Street), a Lewis Carroll-inspired bar that is cosy and slightly disturbing (in the best possible sense) at the same time.
To step things up a gear and check out some music, you'd do a lot worse than try Cargo (also Rivington Street), a disused railway yard (nicer than it sounds) where some of the areas best events take place.