Depends on how long you plan to hold them, and which way you think inflation is going. If you are not holding for 5-30 years, you automatically forfeit the last quarter of interest earned when you sell them.
If you think inflation has peaked, which it seems to have, the composite rate is likely to drop. The base rate is currently only 0.40%
https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/
I bought iBonds in 2021 and 2022, but I’m not buying any more. If you’re still worried about inflation, I think TIPS are a slightly better choice over iBonds
https://www.treasurydirect.gov/research-center/history-of-savings-bond/comparing-tips-to-i/
If you want the most flexibility with shorter-term rate, 4/8/12 week T-Bills are pretty hard to beat.
For CDs, a lot of discussion over in