A lot of weekly series -- including "Dr. Quinn, Medicine Woman," "Nurses" and "Cafe Americain" -- provide new holiday episodes tonight, but the one not to miss is an hourlong episode of HBO's "Dream On," which climaxes with a pregnant woman in a manger in a town called Bethlehem. Pennsylvania, that is.
* "Dr. Quinn, Medicine Woman" (8-9 p.m., WBAL, Channel 11) -- Diane Ladd guest-stars tonight in a ghostly role as an ethereal guide, taking Mike (Jane Seymour) on a tour of Christmases past, present and future. Where the Dickens do these TV writers get their ideas? CBS.
* "Cafe Americain" (8:30-9 p.m., WMAR, Channel 2) -- Stuck in France for the holidays, Holly (Valerie Bertinelli) goes home with Marcel (Maurice Godin) to visit his family. NBC.
* "A Musical Christmas at Walt Disney World." (9-10 p.m., WJZ, Channel 13) -- I guess it's a better title than "An Hourlong Commercial for Walt Disney World." Humbug. ABC.
* "O Pioneers!" (9-11 p.m., WBAL, Channel 11) -- Jessica Lange stars in this 1992 "Hallmark Hall of Fame" drama, one of two versions of Willa Cather's novel dramatized on TV that year (the other, on "American Playhouse," was better). But it's a decent adaptation, and features good supporting performances by Heather Graham of "Twin Peaks" and David Strathairn of "The Firm" (and, earlier, the wonderful "Days and Nights of Molly Dodd"). CBS.
* "Nurses" (9:30-10 p.m., WMAR, Channel 2) -- Another Christmas show, this one borrowing its plot not from "A Christmas Carol" but from O. Henry's "The Gift of the Magi." NBC.
* "Dream On" (10-11 p.m., HBO) -- There's no virgin birth on tap in this Christmas episode, although there is an end to someone's virginity. Written by the show's original creative team, this particular "Dream On" is a howl, and Wendie Malick and Brian Benben, in their childbirth scene, are outstanding. Technically, they're in sitting, but you get the idea.
* "Saturday Night Fever" (10:50 p.m.-1:20 a.m., TBS) -- Well, it is Saturday night, and the '70s are back in a big way, so here's the 1977 movie that encapsulates the entire decade at its best and worst. Well, make that the worst.