I’ve tried quite a few different ones, and have come to the conclusion that some people are much more fussy about the colour of the light than others. For example, I tried some £4 LAP ones from Screwfix, based on reviews saying that they were a “perfect” replacement for halogens, but to my eyes they were a horrid yellow colour, and they went straight back.
My current favourite is Philips LEDspot MV Value 5.3W – £8.50 from http://www.energybulbs.co.uk/ and you can get 10% of with code AUT10 for the next few days.
I’ve also tried the Philips 5.5W Master bulbs, which look a bit smarter, but as far as I can tell give the same light for a bit more money.
The 6W Megaman dimmables are also a very close match for halogens, but the colour is very slightly colder/greener than the Philips, and I’ve had a few failures.
If you actually want dimmable bulbs, then none of the above look anything like halogens when dimmed. The colour temperature of halogens drops to a very warm orange/red colour when they’re dimmed, whereas the colour of LEDs stays the same, making them appear very cold. The only LEDs that I can find that get close are the Philips Dimtone ones. I’ve got a handful of these in my living room, but they’re nearly £20 a pop.
I’ve also got some much older Philips LED ones – the current range is much better in terms of both colour and brightness.