Yves Saint Laurent Intense Lengthening Mascara, or the Volume Effect one (Brilliant! But quite expensive)
L'Oreal Double Extension Ultra-Lengthening Mascara (has the white 'base coat'. These are good, but prone to gunking up quite quickly)
L'Oreal Telescopic Mascara (lengthens and defines each lash. Makes you look like you have 1000 lashes!! You will need at least 2 coats to thicken lashes though).
Lancome is another name to trust for brilliant mascara along with Yves Saint Laurent.
Their newest called Flex WP is hard to beat as it's non everything, apart from making you look stunning without the Spider Woman effect. The wand is ergodynamic making it the most comfortable to use as an added bonus.
You're welcome poppy, but you might want to buy the YSL (�13.50) yourself and put the Lancome (�17.50) mascara on your Christmas list - as this one is the more expensive one.
Worth every penny though as they both last for ages - and significantly cheaper online.
Rimmels new mascara is amazing, the magnifies one, it makes your lashes really long. It's usually �6.99 but its only �4.99 in boots at the moment. Absolute bargin!
Also Bourjois volume glamour mascara is really good, I think thats about �7 or �8!
Just in case you wanted some less expensive options for you to buy and then you could put the more expensive ones on your christmas wish list :-)