For anyone in the East, Levington and Wolverstone marinas are the best option.
We use Levington almost exclusively as there is ample free parking, and it gives easy access to the East Coast waters.
Shotley Marina and Ipswich Haven are the friendliest on the Orwell, but have no slips. They do however have extremely good local pubs!!
Campion 645 Allante SC, 350 MAG, Alpha 1, much loved but under used