For me, Bangalore is better. I have been living in Bangalore for 4 years and I have enjoyed every day spent here. What does an IT person want? Work for 5 days a week and party the rest of the days. You can do both in Bangalore. There are many companies settled here. You have lots of opportunities and chance to meet new people. You have lots of places to party, hang out, go out for a trip. Learning the culture, getting better chances, making a career in IT, everything is better here compared to Chennai.