Best New Bank
Now that ING has lowered their rates from 4.75% to 4.0%(update 4.15%) you may be looking for a new bank.
I think I have found a great one that I have been using for a few weeks. It is the GMAC Bank. The website is http://www.gmacbank.com/
The rate is 4.75% which is the highest non-promotional rate in the country. Additionally, you get a Debit/ATM card. They charge no atm fees and they reimburse you up to $6/month for other bank fees. So basically you could use the card twice at a regular atm without worrying about fees. Also, they give you fifty free checks. You can use up to 3 per month without any fees. So between the fee free debit card and the checks, you can "instantly" get to you money as well as you could for a physical bank.
Also, the transfers are lightning fast between your accounts. I initiated a transfer on a Monday. It was in my GMAC account on Tuesday and was debited from my checking on Wednesday. Usually ING takes about 3 days to transfer.
Sign up was easy, although they do a credit check so people in the middle of getting a loan should wait.
GMAC Bank 4.75%
Emigrant Direct 4.5%
ING Direct 4.15%