Once Doom came out on the PC the final nail went into the Amiga as a gaming platform, imo.
I was a die hard Amiga fanboy one day, 2 Amiga's sitting here, both extremely kitted out and one running a massive BBS. The other I used for a bit of gaming, rendering, etc.
A friend picked up a complete built PC which cost less than the '060 card I had in my A4000 and showed me Doom. All my love for the Amiga, I couldn't get past what I'd seen and the writing was on the wall. I was sitting there, thinking Lemmings was one hell of a fun game on the PC, then I saw Doom - was simply no going back, even as much as I hated DOS and early Windows.