Not sure if they have either around Brighton yet, but Second Cup, a Canadian company that now have a few shops around the country, and Coffee#1, owned by Brains brewery, do better coffee than Starbucks, Caffe Nero and the like in my experience.
Costa coffee seems to be appalling no matter where you get it. Yes, I said it, coffee snob shame me all you like.
They've done an amazing job of building a brand on absolutely nothing, no USP whatsoever yet they dominate the market.
Great marketing and business acumen, crap product lapped up...