As a fellow older American who loves Monty Python, the more modern British shows I've enjoyed the most were Green Wing, League of Gentlemen, Peep Show, and Doc Martin. Of those, League of Gentlemen and Green Wing have the most Python-like absurdity, while Doc Martin has the most subtle humor. Peep Show is hilarious, but the most crass humor of those listed, although League of Gentlemen doesn't shy away from crassness either.