Montagne Jeunesse Fudge Sauna Face Mask. It costs 98p, so whilst I'm saving up for my hols (and coming to terms with the public sector pay freeze, d'oh) this is the perfect treat, it smells yummy, feels warm and comforting on the skin and makes your skin feel lovely afterwards. The Honey & Cream one is amazing too but seems to be a bit harder to find.
However, this doesn't mean I'm not coveting other stuff (see my wishlist!). It just means I'll wait until after my holiday to buy it (plus my birthday's in September so I'm hoping a few heavy hints dropped in August will lead to good things!)