If you need a good streaming box for any of your TVs, the excellent Roku 3 is down to $77 today on Amazon, which is within a few bucks of an all-time low.
Update: Sold out. Hope you got one!
Odds are, you already have a streaming box hooked up to your main TV, but today's a great chance to outfit the rest of them on the cheap. Woot is selling refurbs of the current Roku lineup, and you take home a Roku 1 for $35 shipped, a Roku 2 for $45, or a Roku 3 for $67.
Roku is branching outside its video streaming roots and bringing casual games to its set-top boxes this summer.