Outside of Amy Poehler and trenchant “Weekend Update” jokes, Saturday Night Live doesn’t have a whole lot going for it these days. But it is smart enough to keep recruiting the magnificent Alec Baldwin to host. The blue-eyed movie actor turned up for his 12th go-round this past weekend (a record he now shares with John Goodman; Steve Martin has one less) and almost single-handedly earned all the show’s laughs. He’s not even really a host when he’s on: He’s like a top-dog cast member, the guy in the ensemble who’s so freakin’ comically gifted, ballsy and committed — but never desperate — that if he actually were some unknown salaried player he would be discovered instantly à la Chevy Chase, John Belushi or Eddie Murphy. (He even gets his hands dirty acting in the pre-credit sketches and filmed commercial parodies, which guest hosts usually avoid.) Baldwin’s effect is like spice on stale food. While hacky celebrity impressions unfortunately rule the show now, Baldwin had me in tears with a pitch-perfect Barney Frank, his hipster-addled Tony Bennett, and a tweak on Gabby Hayes in a Brokeback Mountain lampoon about gay prospectors. His kvetching Saddam Hussein was like a slice of classic vaudeville. He makes flirting with the obnoxiously unfunny Horatio Sanz in drag worth watching, and can even enliven the sketch graveyard that is SNL’s last half hour with his hilariously laser-like focus alone. There’s a sense that the writers work harder when Baldwin’s on call, but what’s blazingly clear is that he just knows how to turn up the wattage on this creaky comedy institution. If he weren’t busy being one of the best character actors in movies, he could join the cast and be the funniest guy on television.