Yeah, legacy is the most expensive. There is a small difference between segwit and taproot, but taproot will be most cost effective and very popular for lightning channels, utxo sharing schemes, and other L2 protocols built on top of lightning.

For single signature wallets, segwit will be the most cost effective, but if you want to hide in the crowd, i.e. you don't want your address to stand out as "probably a single sig wallet", then you may choose to use taproot anyway.