One area in which Barcelona does not lack, is places to kick back, relax and have a few copas of vino tinto with friends. What makes Barcelona's thriving bar scene so great, is the informal nature of the majority of the locales. Even if you're frequenting one of the city's classier bars, it's hard to find a Barcelona establishment that's 'too cool for school'. You can show up wearing flip flops and a t-shirt and mingle with locals, expats and tourists all together on an outdoor patio, sipping cocktails and cervezas (beer).
Barcelona's bars are usually open from 8pm – 3am or 4am, at which point its best to move onto a club if you're in the mood to keep the party going. Ciutat Vella (Old City) is one of the best places in town to bar hop as most bars are found within close proximity of each other, so if you've had enough at one place you can cross the road and check out another. Passeig Del Born in the Born neighborhood is ripe with vibrant & lively places to grab a drink. No Name Cafe actually serves free tapas from 8pm onwards with every drink that you buy & Pitin bar is another staple in the Born with two stories, a great wine selection in a very relaxing atmosphere.
Right across the way, the Gothic Quarter has an abundance of bars nestled amongst several nightclubs, especially around Plaza Reial; this is always a great choice for a fun evening out. The Eixample district, up from Plaza Catalunya also has an excellent selection of trendy bars, some of which are slightly posher than the ones in the Old City - yet still very unassuming and down to Earth.