I have bunch of EPS vector files that I want to convert to Xaml (WPF version, not Silverlight). What's the best tool for the job (Preferably a free one)?
You can use Blend (3+ only), to import EPS. Not sure about free tools, but if it's a one off you could just grab the trial of Blend 3.
Correction:
You can't import EPS with Blend, only .ai. You can convert your EPS to .ai and then import into Blend.
Alternatively, there's similar question here that might help.