Weeknight wines ought to be undemanding, like easygoing comedies rather than Ingmar Bergman films. They need not require rapt attention, but they should be delicious and refreshing. And if you do choose to focus on them, you should be rewarded with something of interest, a touch of nuance or complexity that would repay the gift of your attention.
Did I mention price? They should be relatively inexpensive and great values, which are not necessarily the same thing. You can find plenty of innocuous wines for $10. Most will be sound but boring — paint-by-numbers facsimiles of more interesting bottles. They are cheap, but where is the value?
In the range of $15 to $20, however, the level of interest and excitement rises exponentially over $10 wines.