I've been running PFSense on an old Acer Aspire (now called veriton) and it's worked decently well for home use (100 Mbit downstream internet). It's only real downside was a single gigabit NIC, so I had to use VLANs and a router-on-a-stick configuration on a managed switch.

Since the hardware is aging (and I want more NICs for no good reason) I recently found the edgerouter from Ubiquiti. It's running a modified version of Vyetta/vyos and shares its powerful CLI. It's also dirt cheap at <$100 and has been said (I haven't tried to max it out yet) to handle 500Mbit throughput.

So far I haven't found anything that it can't do. It will also POE a few Ubiquiti access points, if you are into those. Makes a really nice home setup for the home network engineer for <$200.