George makes an interesting discovery in the first season finale ... but it's nothing like the bomb that gets dropped on Meredith in the form of Addison.

From the second season, perhaps the show's best-ever episode with the tension gripping viewers from start to finish.

Part three of a three-part story arc to end Season 2, "Losing My Religion" may be the most memorable and talked about episode of any show in the last decade. The interns' interrogation regarding the LVAD wire ... the prom for Richard's niece ... Burke's hand tremor in his right hand ... Denny's marriage proposal and his tragic demise ... Meredith and Derek's long awaited hospital hookup and the ultimate cliffhanger of whether she would choose him - and what the fallout would be. Truly epic television.