Well, wars may one day be fought over gin preferences, but provided it's not the insipidly pointless Gordons or the overdone Bombay, it's a good start. Silent Pool as mentioned (and it's a nice bottle). There's loads of local produced gins now (the offy in Sevenoaks, I noticed the other week, had no fewer than three) – they're not always fantastic, but hey, they have terrior value.
Hendricks, while mostly ubiquitous these days, is a good slightly off-piste gin. You probably can't go wrong with Monkey 47, Filliers 28 (no, I don't know what it is with the numbers), Ableforth's Bathtub (or Old Tom) Gin, or Warner Edwards. You can splurge on something like Oxley. There's very few bad gins and after a few you're naturally inclined toward generosity.