Every time I buy a DVD movie, I rip and convert it on my WinXP machine down to an .avi file of about 700-ish MB and then I use VLC to watch them. Having movies down to this size and saved on your HDD is brilliant for when you're traveling as you don't have to carry all your DVD's with you and as an added bonus, you don't have that annoying noise of your DVD drive spinning away.
Anyway, VLC is a good player, but then again, so is the Totem Movie Player.
On my Linux machine I use both (TBH mostly VLC), but on the XP box, I use VLC
I suppose it goes down to what file extension you want to watch and also the "looks" of the player. Going on looks, VLC is bland and boring compared to Totem which is much more colourful and sexy...
If you still cannot make up your mind on choosing one; flip a coin or go "eenie, meenie mynie mo..."
PS. quickstart, whereabouts in Hants do you hang out? - I'm also from that neck of the woods.