Hmm, so many really good ones. Not in any order but these are the best:
- 1994 Shoemaker Levy 9 impacts on Jupiter. Incredible to watch.
- Imaging and seeing the Venus transit 2012.
- Seeing a Russian rocket re-enter over Adelaide about 5-6 years ago. It covered the entire sky. It made Skylab look like a smudge. About 5 people from our society saw it and a couple of guys that used to visit here also saw it.
- My first total solar eclipse - 2002 Ceduna eclipse.
- Actually seeing 9/10 seeing whilst imaging Jupiter.
- Comet West in 1976 (my first comet), not the best but certainly memorable.
- My first visible aurora (cycle 24). I had surprisingly never seen one before, despite having the opportunity to see one.
The best out of all of the above, would be my first total solar eclipse. It resulted in us seeing a further 2 and planning to see more when time and money permit.