There's a fantastic little Kickstarter running at the moment (that's already fully funded) for a new range of contemporary zombie miniatures (as well as a selection of survivors, barricades, street furniture etc)
The campaign runs until January 10, so won't interfere with your pre-Christmas shopping, and it's worth checking out the fundraiser's page to see what the incentives are for investing - as well as getting a look at diverse designs for the various characters in this line of miniatures.
Pledge before Christmas Eve and you get a complimentary zombie Santa with your rewards.
Meanwhile the various accessories available through this Kickstarter are not only great for zombie-themed wargames and RPGs, but would be useful additions to your tabletop Mars Attacks! games if you also supported that hugely successful Kickstarter.