I have several...
One is the "Vacation Account". This is an online account (Ally Bank) that earns about 1% interest. It is a MMA with ATM access and I get 6 transactions (deposits or transfers) per month with unlimited ATM withdrawals. This account receives $75 every 2 weeks from my paycheck and the money is used ONLY for vacation-related expenses. The money is direct-deposited from my paycheck and I never "see" it so I don't even miss it. This has been the best way that I have found to save for my vacations. I found an amount of money that will be substantial enough to provide a decent boost to the vacation budget, but it is not enough that I will need it to get by each month.
I have a second account set up with EmigrantDirect. I really should move it to Ally too, but I have had it for 10 years and I just haven't gotten motivated to move it yet. This account is for my DVC maintenenance fees. It only earns a measly 0.50% interest, but it is a regular savings account so there is no limit to how many transactions I can make. It is an online account so there is no ATM access. I deposit $110 every month into it and then whenever there is a good deal on Disney gift cards, I will use the money in this account to buy the gift cards to pay our DVC dues when they are due in January each year.
The third account I have isn't really exclusively for vacation money, but that is mostly what I use it for. It is my "plasma fund". I have a SAVINGS account with Ally Bank. It is an online account that earns 2.2% interest but there is NO ATM access and it only allows 6 transactions per month. Every time I accumulate $300+ on my plasma debit card (which, at $90 a week, is about once a month), I transfer the money into this account. Since I try and donate plasma twice a week, I can earn a decent amount of money. I try to save it towards vacation expenses, but I really call it my "fun money". DH donates as well and we both agree that we are allowed to spend the money on whatever we want without judgement. Once it's gone, it's gone. Since there is no ATM access, the money is not easily accessible so I cannot "impulse" spend with it.