I don't have separate accounts -- I have a single savings account that holds our emergency fund, slush fund for repairs, car replacement fund, vacation fund, and the beginnings of a downpayment fund (this last one, I'm considering moving to it's own account, but undecided yet).
Basically, I just have a big pile of money in there, and I just know that the first $12k is our emergency fund. The $2k on top of that is our slush fund (car repair, med bills, etc -- we live in an apartment so no home maint costs). The $9k on top of THAT is our beater car replacement fund. $3k on top of that is for vacation (reimburse cc's for flights, paying cash for vacations, etc), and then anything going on top of ALLL of that is the beginnings of a downpayment. However we really are undecided on buying a house within the next few years so we aren't really aggressively pursuing this. Our apartment is such a good deal in a great location that we are reluctant to move at all.
Essentially, the way this system works is like one of those fancy champagne glass towers. Money comes in and flows down to the foundational "funds" - the emergency fund and slush fund. Only after those are completely filled does money overflow and begin to fill up the other funds. If a fund has to be dipped into, then any incoming money is mentally reserved for replenishing that fund. We add $500 per month to this "super savings" account.
Let's, say our savings account has $25k in it. That means our emergency fund, our slush fund, and our car replacement fund are all fully funded, and then we are ~halfway to filling up our vacation fund. We haven't gotten to the point of putting anything into downpayment though. Now, let's say we have a big, unexpected tax bill to pay off, like $5k. So now the super savings account only has $20k in it -- we used up all our "slush fund" and part of our "emergency fund" for this $5k bill. But, I still have $20k -- so this means I technically actually still have a fully funded emergency fund and slush fund, and most of our car replacement fund still there, but our "fun" fund (vacation payoff) has been totally depleted. But because for our circumstances, the vacation and downpayment "sub funds" are not essential, so it's ok for me to slowly replenish these over time with $500 a month. We end up dipping into our super savings account so rarely that we add much, much more than we take out.
This system works because I am pretty strict about it, but I also like that it allows for flexibility if need be, and I'm not shuffling money around to 20 different accounts. If my slush fund is $2k but I get a $3k bill, its not a big deal to "borrow" from my other funds -- it just gets naturally replenished over time. This is because at any one time, I'm not using all of the sub funds at once. If we lose our jobs and dip into our emergency fund, I'm not also going out to buy a new car and go on vacation. So this allows for a bit of flexibility and flow between the funds, for whichever is taking priority at this point in time.
edit: also, we keep a month buffer in our checking account, so another $3k, on top of our paychecks coming in (which automatically get allocated and distributed to investments, savings, bills, etc). So just that buffer alone means we can absorb the impact of most higher bills that come our way and almost never have to dip into the super savings account, except in cases where the bill exceeds what this buffer could absorb.