You're best bet would be to stay in L'Example, left or right side, that way you'll be in the center of the city and within walking distance of most every thing interesting. The city is full of night life, and some very late night life at that. But don't expect to do much late night tapas/bar hopping without having a plan. Tapas bars in Barcelona are not the same as they are in Madrid or in the Basque country.

A budget would be helpful in making hotel recommendations.

thanks! budget wise, hoping to stay somewhere around 150 euros per night.

Can you say more about the need for having a plan for tapas/bar hopping?

Thanks!

Depending on your dates, you can check the Granados 83, Gran Via 678, Up Suites Bcn, Petit Palace Boquería, Hesperia Ramblas, Eurostars BCN Design and Hotel Atlantis.

If you're planning on having dinner, then you'll need reservations. If all you're looking for are tapas or other small plates, then you have to know when to arrive. There are only a few tapas bars in Barcelona that are similar in style to what you will find in Madrid and the Basque Country, most have tables, and seats at the bar, no standing at the bar. If you don't have a reservation, or don't arrive at the right time, you could end up waiting outside for an opening, which may take awhile, as what often happens at Paco Meralgo.

Irati Taberna Basca, at Caardenal Casañas, 17, in the Gothic Quarter, is one of the traditional Basque style pintxos/tapas bars, open until 12:30 am. You can stand at the bar, or reserve a table in the back. Taktika Berri is one of the most authentic Basque pintxos bars in the city, and always busy.

The vibrant El Born disitrict has got lots of great tapas bars, clubs and nightlife and is close to everything. About El Born district:
http://www.barcelona-tourist-guide.com/en/areas/el-born.html

El Born nightlife:
http://gospain.about.com/od/thingstodoinbarcelona/tp/El-Born-Nightclubs-Barcelona.htm
http://www.barcelona-life.com/barcelona/nightlife

I like almost 24/7 bar/restaurant/cafeteria Navia just opposite the majestic Estació de França to wind down with a drink or some late night food together with locals. Often groups of friends come in here after midnight for fairly huge meals, and it's popular with both night owls, police officers and other night workers for a coffee, a drink or a bite into the morning.

KImhe, I thought Navia closed at midnight? Please update me. Thanks