Delhi has a cluster of really good pubs and bars. Apart from the one available in each of the Star category hotels you will find a good one in each of the markets or malls of Delhi and around. Try Q'ba and TGIF at Connaught place or move to Bacchus at Basant Lok Market. If you are above 40 and want a quite place then go for 'Days of The Raj' at Aurobindo Marg or ' Gaylord' at Friends' colony community center.
http://www.nightlifedelhi.com/delhi-bars.html