It amazes me whenever we discover some new particle, or manage to contain some horribly unstable exotic matter for fleeting moments of time. The search for the Higgs Boson is pretty exciting to me, even though I don't understand much about physics of that sort.
I also love reading about paranoid doomsday scenarios involving exotic matter experiments that spill out of the lab and end up instaboiling the planet into a hot soupy blob of quarks and neutrinos.