If an apple a day keeps the doctor away, then this is the weekend to keep your Granny Smiths in the crisper.

Why, you ask? Because tonight marks the U.S. premiere of the scary-good Doctor Who (SciFi, 9-11 p.m.), the latest update of the British institution about a time-traveling alien who zips about the cosmos in search of adventure. (Get EW’s full scoop here.) Even if you’re not a big sci-fi fan, you’ll want to at least sample this funny, suspenseful series, if for nothing other than the delightful chemistry between The Doctor (Christopher Eccleston, pictured) and his sidekick Rose (pop singer Billie Piper). Of course, if none of this sounds like your kind of medicine, here are some other ways you can while away your weekend:

-If you spend altogether too much of your free time trying to figure what’s really happening on ABC’s addictive Lost — not that there’s anything wrong with that — then by all means check out the latest theories from EW’s hopelessly obsessed Doc Jensen (then post your own).

-This weekend’s new comedy, Thank You for Smoking, focuses on a character whose motto is kind of the opposite of that old ”first, do no harm” nugget, a tobacco lobbyist played by Aaron Eckhart. EW’s Lisa Schwarzbaum gives it a B+.

-On a related note, you may get the urge to get your lungs X-rayed after watching George Clooney’s smoke-filled Good Night, and Good Luck. My second-favorite film of 2005, now out on DVD, gets an A- from EW’s Steve Daly, who calls it an ”accomplished, heartfelt salute to TV newsman Edward R. Murrow.”

-And finally, since curling up on the couch with a good read has been known to cure many an ailment, Allegra Goodman’s Intuition, focusing on doctors working in the world of pharmaceutical research, is ”a delicate analysis of how an ethics scandal filters through the sensibility of brilliant and brilliantly realized characters,” says EW’s Jennifer Reese, who gives the new novel an A.