but a first time player wouldn't want to miss out on the content).
In my playthrough of Half-Life 2 you at one point get to a segment where a giant door closes and you have to get off your boat and run through a segment to be able to open that door.
I completely bypassed that part by driving the boat into the sewer pipe (I think that was what it was anyway) and landing my boat on the railing from which I could get off the boat, push it back into the water, run up and push the button to open the door and continue forward. To this day I have not played through that segment legit XD. Not really a glitch though, just exploit of the physics engine.
(U)MVC3 has had some funny glitches. Like Dooms infinite missiles glitch, or the Z glitch where the axis the characters fight on is rotated 90 degrees. Both are fixed now though =/.