Most people don't get much of a choice and honestly, get what you can as soon as you can.
Despite the efficacy rates, which are highly flawed, all are better than nothing and all probably work pretty equally well.
Typically...
First shot is a mild, unless you've had Covid, then it will feel like a second shot does to most people.
Second shot will be worse.
For anyone thinking screw the second shot because the first sucked, however bad the first one was, Covid is worse. Imagine that for 1-2 weeks, and hopefully without any lingering effects, which is almost guaranteed (just not talked about). The shot sucks, Covid is worse, get the shot.
Also, something they aren't telling people is the milder symptoms and how long they can last.
Weird dreams, started with Covid and lasted 6 months, got the shot, they came back, lasted week and a half
Weird random aches and pains or itching - Lasted a few weeks, came back after the first and second shot.
Unable to sleep, sleep pattern wrecked - Lasted a few weeks, came back after the first and second shot.
Queazy stomach, started just after Covid and lasted 5 months, came back a few days after shot, went away days before second shot. Returned for second shot.
And this was in multiple mild cases of people I know, including myself and a nurse, who herself wasn't even aware of this until we started talking about it.