I had Moderna. It's actually the one I would want because I/we have given so much of it (hundreds/thousands of shots) and everyone, with rare exception, has come back for dose 2 and told me that their immune response was mild and they had no significant side effects.
I also didn't have significant side effects after Moderna. The few reports that I heard from people whose friends and family got J&J were positive too though.
I haven't heard much about Pfizer.
How does it feel to be 1st gen GMO human?