I just played through the Legendary Edition and am going through Andromeda now. While I think ME1 is definitely the best, they all have really interesting mechanics that spice up each subsequent game in the series. I was presently surprised that Andromeda took a lot more risks that, imo, have been paying off so far.
Weapons ammo retcon was done very clumsily and broke the lore established in the first game. If they wanted to change the gameplay and make players break cover more often, they should have just hand vaiwe this issue without explanation.
I had most of my fun playing ME1 trying to take ridiculous long shots on targets outside of the radar range. With some configurations of mods, which ME2 also slashed, this was really effective and kind of hilarious. Some of the physics damage mods on sniper rifles would blow enemies right into the air.