X1 was my first Mega Man game ever and got me into the series. My childhood friend owned a copy and we weren't able to get very far as kids but we liked to play it anyway. It's still my favorite of the X series! I didn't play the other X games until years later. Back in 2015 a guy in my city was selling a complete collection of all the SNES Mega Man releases, albeit in Japanese (so, the SFC versions). A North American SNES can play Japanese games if you rip a couple of plastic tabs out of the cartridge slot, and Mega Man games aren't too dialogue heavy so I was fine playing them in Japanese.
If you haven't played beyond the SNES games, I'd recommend giving X4 a shot. I didn't play it until Mega Man X Legacy Collection released, but it's actually very good. Beyond that... X5 the quality drops off quite a bit, X6 is straight up bad, X7 is also very bad and features a horrible attempt at transitioning the series to 3D. X8 I only played through once but was a bit of a return to form. But yeah, the X series isn't known for consistent quality.