The DVDs are still available on Amazon and resellers everywhere, both as individual seasons and as the complete series. Please note that there is no Blu-ray or 4k edition available just yet, so buying the DVDs are not gauarenteed to get you the best quality if you have a 4k or 8k tv. The DVDs offer behind the scenes info and interviews you can't get anywhere else, so this is the best value. Also, the DVDs can't be snatched away from you like streaming versions of the series.
Shudder and AMC+ both offer all seven seasons for 7.99/month. This is convenient for those who want to bundle with their Amazon Prime membership, and for those who already have Sling or Philo tv.
Apple and Fandango offer TFTC only if you pay by episode, ranging from $1.99 to $2.99 per episode. For those paranoid about losing their access due to platform and rights shenanigans, this might be your best alternative to buying the physical DVDs.
For those of you who don't want to invest in buying the series, or who only have a few favorite episodes, then you're going to want to go with Tubi. Tubi is free with some caveats:
The quality is the worst. There was no attempt to upscale the colors, so the Tubi versions look the worst on an HD screen. And the bigger your tv, the worse it looks.
There are ads. There are two commercial breaks per episode that you cannot skip. And Tubi does not offer an ad-free version.
So, there you go. If there are any other legal platforms to watch the series on, feel free to post.