Depends on how girly your other half is to be honest and your budget...
Massage
Manicure & Pedicure
Hairdresser vouchers
Shoes (be careful)
Perfume
Jewellery (get something engravable and be sentimental ;)) or a jewellery box
If you've got kids Vouchers for a photographer who does quality family photos?
A framed photo of the two of you (could be recent, could be from years ago) with a note on the back of the frame
Hotel for a night, dinner, sleep in, fluffy bath robes.
If she decorates cakes, the new planet cake cupcake book (have a family member who would kill for this)
If she loves to bake (biscuits, cakes etc) one of those kitchen aid mixers?
If she loves to cook (not cooks for love) any of the new release cookbooks...pick a recipe from the book, make a hamper with the ingredients and cook it together?
Something in the tech area...laptop, ipod, ipad, kindle, new camera
A set of wine glasses, her favourite bottle of wine and a box of her favourite chocolates....or a basket filled with her favourite foods (make your own hamper)
If she loves IKEA a gift voucher?
Tickets to a show...a musical, drama, opera, ballet, comedian
A purse or handbag
See if you can have a bouquet of flowers delivered on Christmas day? (interflora maybe)
If she likes natural products go to the Body Shop and have them make a hamper for you or purchase a ready made one?
Dinner at a nice restaurant
A novel/paperback by her favourite author
A Nikon D90 with lenses, SD cards and Bag (you had better read this Simon, I'd really really love you :p but have to kill you for spending too much :()
If she enjoys gardening, new gloves, tools, a plant or three, plant pots, water feature
If she loves diy new tools, a new tool box etc
If she loves art and you know her style you could get her an art print? deviantart.com has free shipping around this time of year and thousands of artists to choose from. I purchased this for the other half last year deviantART Shop Framed Wall Art Prints & Canvas | Photography | Urban & Rural | Good Morning, London. by artist `geckokid
Edit to add - DVDs from ABC shop or SBS (Dymocks I believe)...Any of the series they just HAD to watch in a DVD set is always a good idea
La Premiere or Gold Class Movie Vouchers (where you sit in the comfy recliners and get delivered food and drink before and during the film)...you may have to let her choose the film as well ;)
OH! A 2011 Land Rover Calendar! :D:p Then she can write your anniversary on there and you'll not forget!

