Nini I entirely disagree from you by putting this splendid group like IRS on 4th. After meeting different CSP I will ask you to put IRS on top of group preference list because according to different CSS officers IRS has no match. Police, DMG were good groups but now the trend is changed and modern period belongs to groups like IRS and PAAS. I met people of Police and DMG group and the stories and difficulties they tell about their groups are very sad. In finance related groups like IRS and PAAS promotion are excellent and working conditions are very good with a lot of chances of success. The financial powers are amazing and read news articles where new powers given to IRS group are awesome. IRS is a new group and first few batch officers will be on the top position after 10 years that is why in 2010 batch a good number of people have put it in top choices. My top 5 choice list will be following

1. IRS
2. PAAS
3.Customs
4. Foreign Services
5. Police