Free games is always a good thing, especially when it's the best one in a trilogy. Mass Effect 2 is now free on Origin under their On The House program. Simply head to the link and start the download.
Perfect timing too since Bioware just announced the release date of Mass Effect: Andromeda. Andromeda isn't a continuation of the first three games, it detaches itself from Shepards story, and you follow Ryder's journey to the Andromeda galaxy. But Mass Effect 2 would be the perfect introduction to those that haven't tried Mass Effect. So, give it a shot - it's free for a limited time.