The departure of Fox's House has made this timeslot a little less brutal in the fall, but in the spring American Idol should remain the unquestioned champ.
ABC: This timeslot has been quite an adventure for the alphabet. In '06-'07 the slot was filled with Dancing with the Stars originals in the fall, America's Funniest Home Videos repeats, Dancing recaps in the spring, and the occasional original of eventually-canned George Lopez. ABC decided to try a little harder in fall '07 by launching comedies Cavemen and Carpoolers, and both started decently but had big-time fall-offs and were gone by November. Then in January came an unsuccessful regular season run for summer sleeper success Just for Laughs followed by a disastrous stint for According to Jim. Fall of '08 saw more troubles with reality duds Opportunity Knocks and Homeland Security USA, more Dancing recaps, and more According to Jim. ABC may well be back in the reality dud business here with Shark Tank, although this time the show will have aired several episodes before the regular season begins. Based on the shaky summer start for Shark Tank, good old Dancing recaps could show up again in the slot leading up to the premiere of midseason sci-fi drama V in early November, a change of pace in a slot where drama has been nonexistent for ABC in recent years.
CBS: Unlike the troubled ABC, CBS can sum this timeslot up with just four brief letters: NCIS. The show had something of a resurgence last season thanks in part to much better options at 9PM and 10PM than the net has had historically. It was one of the largest gainers in last May's sweep and one of the very few shows up year to year overall, rising about 3 ticks from a 3.35ish avg. to a 3.65ish in '08-'09.
FOX: They always have the dominant American Idol here in the winter/spring and will again so let's get that out of the way. They started '06-'07 with medical drama House here leading into newbie Standoff but once it was clear Standoff was a bomb, they brought it back from hiatus in the 8 slot while maximizing House's ratings at 9. In fall of '07 they assembled a very strong evening by putting Bones in the 8:00 slot, where it benefited from the House lead-out. In '08 they opted to use House as a lead-in again, this time for JJ Abrams newbie Fringe. But a night that has been House-centric for so long will no longer be, as House is off to Monday and this timeslot will be populated by the first half of a two-hour So You Think You Can Dance. Don't expect House-type numbers.
NBC: The fairly unsuccessful launch of new drama Friday Night Lights took place here in fall '06 and NBC moved Dateline to the hour in the winter to go up against powerhouse American Idol. In fall '07 it was The Biggest Loser joining the slot to fairly successful results. At times it was shortened to 90 minutes so a half-hour edition of summer hit The Singing Bee could air at 8:00 but the Bee was a regular season disaster and eventually shipped to Friday. Loser was a permanent two-hour fixture for its winter '08 cycle. The early debut of the second cycle caused it to end well before regular season's end so NBC ran Most Outrageous Moments and some Saturday Night Live specials in the hour in late spring. Biggest Loser returned for two more cycles in '08-'09 but ran longer so it could take up almost all of the regular season. The cycles averaged 3.2 (fall) and 3.9 (winter/spring). It joins Sunday Night Football as the only NBC shows to return to the same timeslot in fall '09.
CW: The new network was good to go in this hour when they launched thanks to Gilmore Girls. That was done after CW's first year so they relied on Beauty and the Geek for two cycles in '07-'08 and it weakened significantly by season's end. Reaper repeats filled time between cycles. There was reason to be optimistic thanks to the big debut of 90210 in fall '08 but it had weakened so much by the winter that the net opted to put midseason returnee Reaper in this slot to keep 90210 away from Idol. 90210 returns to 8 this fall to lead into newbie Melrose Place at 9.