Reply to Samples Packs?

I'm new to DJ/production and new to Ableton 8, and I'm wondering about sample packs. There are countless sample pack's available online, is it worth it to invest in one, and if so which ones are the most comprehensive? The Ableton samples seem alright for messing around with, but I don't want to end up sounding like a Ableton version of Garageband. I'm hoping to produce some of my own electro dubstep remixes, etc. Please let me know what insights you have into this topic.