I did one night in Tilaran just to check out LAB (Lake Arenal Brewery). It's like a 20 minute ($5 cab ride) out of Tilaran.
I've seen nicer breweries in my day, but at least the beer was good drinkin. The place definitely needs some love as it looks like it was really in it's price 15+ years ago.
Would recommend for some great views of the lake a a pint of the Pale Ale they have on tap!