9. Being Sucked Into A Blackhole
In "A Matter of Time," SG-10 makes the horrible mistake of visiting PX3-808, a world circling a newly formed black hole. If you know anything about the nature of these astronomical wonders, you know it isn't going to end well for them... and it doesn't.
The bulk of the episode centers around the inability of Stargate Command to close the wormhole. Instead of collapsing like usual, it's sustained by the black hole's energy, which creates a problem for SGC. The anomaly's gravity begins warping time and space, pulling everything to the wormhole, threatening the Earth.
It's all dealt with throughout the episode, but the fate of SG-10 is only glossed over, and theirs is the worst of all. Falling into a black hole is no picnic, and it's easily one of the worst ways to die in any universe. Because of how a black hole warps spacetime, SG-10 is effectively trapped in time.
From their perspective, they run from the black hole in normal time, but for everyone else in the universe, they are trapped in their fate forever. There's also the spaghettification of their bodies as they are pulled into the black hole, which would seemingly take forever.