When comparing photos of Zac Efron from then and now, not much has changed. The actor is always adorable, always the object of every teenage girl's affection.

The years haven't exactly been as kind to Shannen Doherty.

The actress, who returns to 90210 tomorrow night after a few weeks away, hasn't aged gracefully.

She may still portray Brenda Walsh on the small screen, but as these contrasting pictures of Doherty prove, Dylan McKay made the right long-term decision when he chose Kelly Taylor...

RIP, sweet, innocent and beautiful Brenda Walsh.