Depends what compatible means. THe Canon HV40 is tape based and is still available for $600. That's records to HDV and can be edited natively in FCP.
As to other formats, nearly any camera will work OK with FCP, although I would avoid those that record directly to DVD.
Virtually all other consumer choices today use AVCHD, which needs to be transcoded via Log & Transfer. Here is a list from Apple that is a few years old. Many of these models are no longer on the market, but you can find their nearest equivalent. One camera that isn't on the list are those made by GoPro. If you're active in sports like skiing, surfing, or biking and want to record action, look into their equipment.