I find this a good number to have because it builds up your savings as well. While I am constantly putting money into my savings, I have found more uses for my emergency fund besides protecting against job loss.
1) Car Breakdown
Just your luck. Your car decides it needs to breakdown at the most worst time. After you kick your car, it has to be fixed. When the mechanic says the costs are $2,000, you will freak out but in the end your emergency fund is there to help you out.
2) The Once In a Lifetime
Every now and then, there is an expense you just have to have. It is a one time opportunity to experience something unique and once in a lifetime. I recommend taking a hard look at if to determine if it is still the right investment for you, but do not pass up great life experiences. Your emergency fund can be there to provide you with necessary dollars. It is important to recoup the funds so if a real emergency happens the money is available.
The emergency fund provides me with a peace of mind. I know I may not be happy with paying a certain amount of money out, but in the end of the day, I will be able to continue my life and standard of living because I have my emergency fund.
As with most financial goals, you have to be determined and disciplined to fund your emergency account.