I have a top of the line Sonicare one – that goes in a glass to charge (inductively). I bought one of its predecessors years ago and am now on my fourth after them all failing without any reason (apart from one which may have kinda fallen out of a window). So whilst I can’t vouch for their reliability, I can stand by their warranty – all replaced under warranty with no qualms, including me insisting on an upgrade this time and them having failed after the warranty actually expired. They seem to work well too. And they are always on sale.
I've had a simple Oral-b one for years and it's still going strong. my missus has just got her first - it's pretty much the same except it has a built in 2 minute timer to ensure you spend long enough on your brushing.
In reply to Hat Dude:
quiet. however, if not something useful like erm , a tooth brush, what does one purchase for a fell runner ? believe me if imelda marcos was training for a bg she would have less pairs of speed cross and inov8s.