I was getting over 5.365% in Treasury Bills (purchased in $100 increments, with a 4-week maturity), but since the Fed cut rates, it's dropped a bit, 4.783% on issues for October 1st. Still better than just about any bank.
I split my savings up into 4 parts, then bought one 4-week T-Bill every week, and set them to automatically reinvest. That way one matures every week then reinvests for another 4 weeks, so they're constantly rolling over. In an emergency, I can get 1/4 of my savings back within a week, and all of it within a month. Almost all major expenses can be paid by credit card, and I have until the next billing cycle to pay that off, so that's plenty of time to get my money out of the T-Bills if I have to.
https://www.treasurydirect.gov
You can buy Treasury Bills (4-26 week maturity), Treasury Notes (2-10 year maturity), Treasury Bonds (10-30 year maturity), TIPS (5-30 year maturity, inflation-protected), and Savings Bonds (30 year maturity)
Oh, and while you have to pay federal income tax on the interest, there's no state income tax on it. That can be worth a considerable amount right there.
Minutus cantorum, minutus balorum,
Minutus carborata descendum pantorum.