Pros
Working here is great for the resume and if you're straight out of college, most of your co-workers are young so it can be a fun place to be. People are generally pretty motivated, have common sense, and social. There are a lot of smart/accomplished people in management and are resources for knowledge and developing contacts. Deloitte encourages you to use your vacation days and they also participate in community activities like Impact Day which is good.
Cons
The hours can be long. Sometimes while at a client, it's Friday and you're ready to go home, someone will ask you to do something at the end of day which you know will take you several hours to complete. There is a culture of always being a "yes" man, so if you care about your reputation and career, you have to say yes and get it done. Once you make management, it's great to have staff with that attitude, but when you're the staff it sucks at times. Pay is not the greatest. You hear people leaving the firm and getting huge pay bumps or there are people outside of the Big 4 in private who are doing the same thing you do but making more and working less hours. You always have to remind yourself that you're not there for the money and that the paycheck/reward will come later.