Not too obnoxious sports bar in PDX to watch Final Four?
yeah, Spirit of 77 is big enough to almost always be able to get a seat(if you're there before a home Blazers game, all bets are off....it's an unbridled zoo!), and the food, booze, 15ft big screen are all damn good! Prices are a little high, but it's popular and the food really is the best sports bar food in PDX(like by a looooong ways, it's legit food, not chicken fingers and spinach dip).
Last year, the Duke alumni club watch the national title game at Blitz Ladd in Southeast. There were ~20 of us rooting hard for Duke, but the other 80 people in the place were all for Butler. I'm guessing that you would find a similarly friendly crowd there on Saturday and probably Monday as well.
As for Blitz, it was pretty good. No giant screens, but definitely a decent menu and quite a few beers. There are some nice little tables with couches if you get there early.
2239 SE 11th Ave, Portland, OR 97214