This is what I used when I transferred from my 2016 MacBook Pro to my 15" M2 MacBook Air: https://www.apple.com/shop/product/MQ4H2AM/A/thunderbolt-3-usb%E2%80%91c-cable-08-m?fnode=7a24ef1288e68b0741814f89771d2f6949b39798ba2791638e17c8ff789b9421bb94e89d4bf1b84ab50fe4c5bcebe2931caef70652793168b11a9099685b97bca4a3a872a6e5875781b156529e4fb541008b27aac431bd49ecc80fd0113926e9150e991af2edb7e65757224926a0d207
It's a Thunderbolt 3 cable, and I was amazed how fast the transfer went. It took less than an hour to transfer nearly 1TB of data from my old Mac using this.
There are, essentially, four methods of transferring data from an old Mac to a new one with Migration Assistant:
- Via WiFi. As Wheelie pointed out, no cable is needed. However, it's probably the slowest method (and requires a very stable WiFi connection to reduce the chance of data glitches).
- Via Time Machine backup external drive: Up until my latest transfer, this has always worked well. But it can be time consuming, depending on how much data is being transferred.
- Via Ethernet crossover cable: Might be a tad faster than the first two methods, but requires not only the ethernet crossover cable (relatively cheap) but also two ethernet<->USB C adaptors, since neither Mac has an ethernet port.
- Via Thunderbolt cable: The fastest means, as I've described above. For me, it's the most foolproof...but others here have their favorite means as well.
Hope this helps.
(Edited to correct a mistake...I transferred nearly 1TB of data, not 1GB).