Okay, I didn't ask a great question. You say you don't want to replay because you don't feel your choices matter, is that mostly the ending's fault or the whole of 3?
The whole. My Shepard wasn't my Shepard anymore, it was just a random woman on autopilot who happened to bear a physical resemblance to my character; all the "big choices" made in the previous games were ignored, the result was fundamentally the same no matter what; things that previously were hinted at being very important to the story were completely swept under the rug (Dark Energy).
Overall there was a ton of missed opportunities, things that they had the unique chance to do because hey, it was the end of the trilogy, no more games after that so why not go out with a bang? But no, they chose to be boring.
The endings were the icing on a cake made of disappointment, as far as I'm concerned.