I for one can recommend the canaries at xmas, spent new years out there a few years ago and was still VERY warm, but a bit busy cos lots of people go there at that time of year. Other than that the caribbean's pretty good at that time of year i reckon... depending on what sort of destination you want tho (going back to the canaries) you should choose which island you want carefully. Tenerife is more commercial/clubby/young etc, fuertaventura is more coupley, less to do but more culture-ish, gran canaria's a good all-rounder and so is lanzarote, although less commercial again. Lanzarote's my favourite as there's some wicked things to do as well as bars/beaches and lazing around...