Plot: A few memorable plots brew in the fifth season, including the budding relationship between Callie and Arizona, Derek and Meredith's engagement, and ugh, Izzie's heartbreaking cancer diagnosis. The characters grow more vulnerable, especially Meredith when it comes to taking the next step with McDreamy and Alex when it comes to taking care of Izzie.
Ending: George gets hit by a bus and is admitted as John Doe at Seattle Grace. Since his face is unrecognisable, Meredith only realises who he is after he draws O-O-7 into her palm. Then, Izzie flatlines, and everyone decides to go against her DNR. Cue the iconic lift scene where Izzie wears her hospital prom dress and sees George in an Army uniform.
Weepiness: Season five gets five out of five tear-stained stars for its heavy dose of romance and drama.