Sweet Carrot Varieties?

[Bluemoon]

Can anyone recommend a really sweet carrot variety? I have clay soil and usually end up growing my carrots in containers, but the only ones which have been successful this way are Paris Market types and they're really too strongly flavoured for my taste. I've tried harvesting Chantenay whilst young as I've eaten tiny versions of these cooked whole and deliciously sweet , but mine don't seem to colour up sufficiently for me to pull them this early.