How great is NBC's sophomore series Chuck? Last night, it managed to resurrect Scott Bakula and make Chevy Chase interesting.

With the exception of some middling episodes around the middle of this season, Josh Schwartz and Chris Fedak's lovable, feather-light spy series has moved from strength to strength since its return last fall. Stars Zachary Levi, Yvonne Strahovski, and Adam Baldwin were charming from the outset, and the show's first season was pleasantly affable entertainment. But season two has rapidly eclipsed Heroes -- despite that show's recent, tentative creative second wind -- as the main reason I look forward to Monday night TV.

All season long, the characters have gotten deeper and more likeable, and the jokes even funnier. The writers have also gotten really good at finding believable ways for the show's dweeby hero to save the day without magically becoming some sort of badass superspy. In all, Schwartz and Fedak have successfully struck a tricky balance between goofy heroics, honest heart, and, uh, a lot of Subway product placement, for some reason. (And if the show does take particularly nerdy glee in dressing Ms. Strahovski in a parade of mind-boggling, Sydney-Bristow-worthy getups, it compensates nicely by giving her a thoughtful, surprisingly complex character to play.)

It doesn't hurt that the guest casting's been truly geektacular: Jordana Brewster, a surprisingly non-horrible Nicole Richie (getting the snot kicked out of her, as an added bonus), Tricia "Six" Helfer, Andy Richter, Michael Rooker, Arnold Vosloo, and even Reginald VelJohnson sneakily reprising his character from Die Hard. Other shows may land bigger names for guest appearances, but none has assembled a lineup as much fun as Chuck's, nor used them so well.

Last night brought in Chase as a wonderfully smarmy Steve Jobs analogue, and Bakula as Chuck's paranoid absentee father. Chase isn't the first guy who springs to mind when you think "smug corporate overlord," but he did a nicely nasty job of it. And in the space of an hour, the episode managed to remind me a) why I liked Bakula as an actor, and b) that I ever liked Bakula as an actor, period.

After four years of grimacing his way wearily through Star Trek: Enterprise, here at last was the guy I remembered fondly from Quantum Leap. Bakula played Chuck's dad as a shuffly, twitchy, damaged bundle of bitterness and regrets -- a complex, interesting, honest-to-God performance that packed a lot more punch than it probably should have. (Some of the show's strongest writing to date definitely didn't hurt.) And sure, I probably should have seen his character's big reveal coming, but that didn't make it any more delightful or triumphant. Nice to have you back, Dr. Beckett.

It looks like Bakula and Chase will be back sometime before the end of the season, which suits me just fine. Unfortunately, I can't say the same about Chuck's odds for a third-season pickup; like pretty much everything else on NBC these days, its ratings have reportedly been in the tank. (Clearly, too few Americans have learned what Joss Whedon taught us long ago: Adam Baldwin + tranquilizer darts = comedy gold.)

So watch while you can, and hope for the best. While Heroes has flailed wildly around this season, desperately searching for a workable strategy, the other geek-targeted show on NBC's Monday nights has been quietly, consistently, and awesomely getting it right.