Would you renege your lower-tier BB offer for top tier EB?

It seems as if most of the answers are from interns/prospective monkeys...not saying it's not good advice, but here are my 2 cents.

If you think you were a rockstar candidate, go email the Top-Tier BB's MD and see if you can get him on the phone for 5 mins (guarantee you they will...and they should know what's coming).

Tell them you accepted an offer already but would really want to work for your firm and ask him/her for advice. You should know your answer after that phone call. The fact that you got him/her on the phone shows that you're serious and not dicking around. Also leaves a good impression that you're not scared to pick up the phone...rare with kids these days.

I was once in your shoes and did the above. The MD told me these exact words, "Look, at the end of the day you are very young. You can afford to make mistakes. What you think is a big deal now, really isn't. We like you and you have to remember that going forward in your career, you always have to do what's best for you".

I reneged, went to the other firm and made damn sure to make that MD proud!

Good luck!