With two absolute gems back to back, Frasier has left Seinfeld--now off the boil--in rear view. Frasier has aged like fine wine and is one of the most articulately humorous shows the wrong side of the Atlantic. Kelsey Grammer and David Hyde-Pierce are seamless and complement each other superbly. Their antics are a gratifying distraction from the humdrum of the usual prime-time fare. (Tuesdays at 9:00 on NBC.)