Thursday night has notoriously been the night where the networks dispaly their best comedies and dramas. Tonight, ABC, CBS and NBC will air the season finales of their biggest hits in a knock down, drag down out fight for ratings.

CBS will air the season finale of their biggest hit, CSI, tonight which won’t have any major shake-ups in the cast but should satisfy long-time viewers, especially since they know the show will be back for a tenth season.

Over at ABC, the two hour season finale of Grey’s Anatomy will air to great fanfare with Izzie’s life hanging in the balance as she struggles with stage 4 cancer. Derek thinks he can cure her through surgery but there is a risk she will lose her memory. Its not the best time to lose all memory since she just married Alex, not to mention the surgery is risky. There are also rumors this will be the last episode with Dr. O’Malley as it is no secret T.R. Knight wants off the the show, badly.

On NBC, Amy Ryan returns to The Office, as Michael’s long lost love, but, unfortunately, it will b her last appearance on the show. Amy’s character will show up at the company picnic with a new hot boyfriend. You can imagine how Michael responds and hilarity ensures. On 30 Rock, Tina Fey rolls out the red carpet for a parade of guest stars including Alan Alda, Clay Aiken, Elvis Costello and Mary J. Blige. Is anyone else growing tired of 30 Rock’s big guest stars? “Special” guest stars aren’t so special when there is a new every week.