[zeveb]

You might wish to consider these in terms of entropy, which is typically given in bits:

    Diceware, 6 words          77 bits
    Diceware, 5 words          64 bits
    Diceware, 4 words          51 bits
    a-zA-Z0-9, symbols, 10     65 bits
    a-zA-Z0-9, 10char          59 bits
    a-zA-Z0-9, 8char           50 bits

For any remote site, I recommend using 22 characters from [a-zA-Z0-9]; this is 128 bits, and is easily copy-pasteable.

It's highly amusing when a site tells me that such a password is insufficiently complex, given that it will never in the lifetime of the universe be guessed.