Zucca on Bermondsey Street is very good. Pizarro is excellent too, and while they don't usually take reservations, they have a couple of private rooms which I believe can be booked. Elliot's Cafe in Borough Market is decent, and a bit more modestly priced. I've also heard very good things about Applebee's (also in Borough Market), but I've not been personally. Bit of a curve-ball perhaps, but I really liked Tito's Peruvian restaurant (although my wife was rather unimpressed).