My beer fridge, used both for the kegs and bottled/canned brew, stays at 36 degrees. That works for me, with the aim being to retain freshness where colder is better because it slows transformative processes. I pour some of my beers with a little "lead time" and let them sit to warm before drinking. Another trick is to warm the glass. I find mid 40s is the range where flavors bloom more for me, though that's too warm for yellow lagers IMO. It's interesting to observe how a beer changes over a range of temperatures.