Tommy Lee Jones gives one of his best performances in “No Country for Old Men,” opening today, but if he wins an Oscar for this picture it will be for Best Supporting Actor. Though Jones gets top billing, the main role, of an ethereal psychopath stalking a guy (Josh Brolin) who made off with $2 million in drug money, belongs to the unforgettable Javier Bardem, who deserves a Best Actor nomination. But the situation is confused because Bardem is apparently going to be put up for Best Actor for next week’s misbegotten “Love in the Time of Cholera,” for which he doesn’t have a snowball’s chance in hell of getting nominated. Anyway, I give “No Country,” the Coens’ best flick ever and their first Best Picture contender since “Fargo,” four stars in today’s Post. Lots of other pictures opening today, but none are Oscar contenders. In his one-half star review, Kyle Smith quips that “Fred Claus” is “not like a lump of coal in your stocking. Coal is useful; you can burn it. This movie is more like a lump of something Blitzen left behind after eating a lot of Mexican food.” Having seen “Fred Claus,” I’d say Kyle is libeling Mexican food. Also reviewed today in The Post: “Lions for Lambs,”“P2,”“Holly,”“Saawariya,