Moderna:
1st dose - no side effects, very mild arm soreness for a day or so.
2nd dose - not sure. Definitely no side effects other than mild arm soreness the first 14 hours or so. But I went back into work really late for a while, so I got wound up from that, and I ended up getting very little sleep that night, which happens to me somewhat regularly, so I can't blame the vaccine for lack of sleep. I was tired and feeling a little crappy the next day, which could have been due to the lack of sleep, but it's possible the vaccine was a factor making it worse. I confirmed no elevated body temperature. No way to know if the vaccine made me feel any more tired - could have just been the lack of sleep. After a good night of sleep, I felt normal. Mild arm soreness lessened and was gone completely in another day.
I'm 9 days out from my second dose and have continued to feel fine.
I work with a woman in her 40's who felt really dizzy minutes after having her second dose (also Moderna). She went home early and didn't even come into work the next day.