My parents never did much of a fuss around their birthdays. But my in-laws have thrown mighty parties for their big "0" birthdays.

For her 50th my MIL had a surprise party with everyone wearing a "mask" made out a picture of her face as a baby" and lots of silly things, including four friends dancing dressed up in "Full Monty" fashion (probably just a bit more). So yeah, embarrassing but fun stuff. My FIL's 50th was a "cowboy" party (no idea where that came from) with everybody dressed up as cowboys/girls, there were hay bales all over the house, and surprise guests again.

I don't think big gifts were involved though.

It really depends on what your life is like...