Kent has lots of soul destroying places to be honest: Gillingham is far from alone in that respect.
How about Sittingbourne? Dover? Dartford. Thanet. The Isle of Sheppey. Ramsgate. Margate. Chatham. Gravesend. Erith. Bromley. Bexleyheath. Hythe.
Lots of rubbish options to choose from.
Only just seen this but have to take issue with Margate and Ramsgate. Thanet is defintion of down at heel but these two towns have their redeeming features.
First Margate, a beach Brighton would kill for and because of it's heritage as a resort some interesting buildings. Sure the town centres a shithole but like Ramsgate a few miles round the coast it's been decimated by the huge out of town retail parks the council have allowed.
Ramsgate has a brilliant harbour with some nice pubs and reataurants around it which are great to sit in of a warm summer evening.