Netflix

Every time I re-watch it, I always enjoy the finale. I watch the series from the beginning once a year. Would I have chosen something less open ended? Sure. However, at the same time, I do enjoy the finale. And even though they don't show us if Sarah got her memories back after the kiss, they dropped hints of her memory returning (such as how things were rearranged at the Wienerlicious, and the final beach scene. They also kept bring up the true love's kiss returning memories so it makes me believe that with the kiss at the end, Sarah did get her memories back.

The question is, whether she got them back spontaneously, or if they came back partial or in full within days of the kiss. I like to think partial instantaneously (such as when she first met him and admitted to being in love with him in "Chuck VS the Other Guy" and then the rest from then such as the wedding until Quinn erased her memories came back slowly over time.