Rich text: VARCHAR, TEXT or BLOB in MySQL
It would depend on the size of the data you want to save in that field. You should know that there is a limit for VARCHAR, and that limit is in bytes, so number of characters that can be stored will depend on the character set you use. For example, if you use UTF 8, you will be able to store less amount of data.

To sum it up, there is no "best" solution, but if your data fits in VARCHAR, then use it :). If not, you will have to use TEXT or BLOB, or you will have to zip the data before saving it (Check compress)