NBA playoffs: Nuggets at Spurs (6 p.m., TNT); Grizzlies at Suns (8:30 p.m., TNT)

Lost (7 p.m., Ch. 4): If you haven't been watching one of this season's most talked-about shows — or if you've missed some episodes — this is your big chance. This hour recaps everything that's happened to date and gets you caught up in time for the last few episodes.

That '70s Show (7 p.m., Ch. 13): In order to officially graduate, Eric has to take a P.E. class over the summer.

Smallville (7 p.m., Ch. 30): Chloe helps Clark learn about his superpowers after he loses his memory.

Alias (8 p.m., Ch. 4): Nadia may be in danger.

Revelations (8 p.m., Ch. 5): Massey and Sister Jo travel to Rome to find the miracle child.

American Idol (8 p.m., Ch. 13): Another elimination.

Jack & Bobby (8 p.m., Ch. 30): There's a deadly accident after a high-school dance.

CSI: NY (9 p.m., Ch. 2): Stella's tactics might cost her her job.

Eyes (9 p.m., Ch. 4): Harlan investigates when Leslie's companion is shot.