You have not mentioned that is for PC only then understanding it`s for GAMES, then let's get wild :D
+ still having it, - had in past

4-bit KB1013VK ~33kHz : Elektronika IM-02 Pocket +
HT1130 1MHz : Bricks Pocket -
UA6527P 1.66MHz : NES Clone TV Console -
6502c 8Bit 1.77MHz : Atari 65 XE Home Computer -
4-Bit CMOS E0C6S46 ~33kHz : Tamagotchi -
Intel Celeron 433MHz : Desktop PC -
AMD Duron 800MHz or Athlon 1200MHz ; ) : Desktop PC +
Intel Pentium 133Mhz : Toshiba 440CDT -
AY-3-8500 2MHz : Ameprod TVG-10 -
Motorola 68EC020 14.3 MHz : Amiga CD32 -
Intel Core2Duo P8600 2.40 GHz : Toshiba Qosmio F50-12W -
Intel Atom N280 : Toshiba NB200-123 +
64bit Broadcom BCM2837 Quad Core 1.2GHz : Raspberry Pi 3 B +
Intel Core i3-4030U 4CPUs 1.9GHz : Lenovo 20405 +
... coming soon ^

this is surprisingly personal... thanks for the inspiration!
(not including games on mobile phones, tablets or smart TVs, and some more borrowed and tested consoles)

1997 - Pentium 2 - Onboard graphics
2004 - Pentium 4 3.0 Ghz - GeForce 7600 GS passive
2011 - Pentium G620 2.6 Ghz - GeForce 8400 GS passive, GeForce GT 430 passive
2021 - Core i-5 11400 2.6 Ghz - Intel UHD Graphics 730

I don't remember all the cpu's I've had access to, but I know the first one was an x86/286.

I don't remember all of them, here are a few

LH0080A Z- 80A compatible (borrowed)
Motorola 68000 7MHz
80286 4MHz
80286 8MHz (borrowed)
80386 16MHz (borrowed)
Pentium 90 (first 8, later 24 MB RAM)
K6 200, 400, then other speeds
K7
Athlon1,2
Phenom 1, 2
i5 4xxx something
Ryzen 3900x

I think I have 32Gigs in my system since the phenom.

Honestly no idea. Haven't really been tracking my CPU history. I only know that I've been on an i7-7700 since mid-late 2017, when my mobo got killed by lightning (along with the PSU) and had to replace it, so got a new CPU with that. Can't even remember what the one on the killed mobo was.

But I am pretty sure it's all been Intels.

Well, before my previous PC, I only ever used laptops for gaming (I know, but I was a kid and had to take what I got). When I graduated high school, I used gift money to buy myself a gaming PC which lasted me (with minor upgrades) until last Christmas. That PC had an AMD FX-8320 on it and shockingly, it ran more recent games better than you might expect.

Now, on my new rig, everything is 100% brand new (except the GPU, due to GPU prices at the time). On this machine, I'm running an AMD Ryzen 5 5600g. Went for the 5600g not only for its performance but for the option of integrated graphics. I know the GPU I ported over (Nvidia GTX 980) may fail in the near future before I have the cash to buy myself an RTX 4xxx card so having an integrated graphics option at least so I can still do work is certainly something I wanted to have.

And honestly? This CPU is a beast. Maybe not the ABSOLUTE pinnacle but man, it's close. It's to the point where it'll probably give an RTX card a good run for its money in the bottlenecking department.

Pentium 90MHz <-- My first desktop computer with Windows Blinds or something.

Custom 8-bit Sharp LR35902 @ 4.19MHz (GameBoy)

Pentium 166MMX, 266MMX
Pentium III 500

Atari SALLY @ 1.19-1.79 MHz (Atari 7800, bought used late 90s)

Athlon K6 - The first Intel-killer on the A socket. Could cook an egg on it...
1 Athlon XP (+ one on a laptop which didn't go so well)
1 Phenom
1 AMD FX-xxxx

A couple of Pentium 3 and 5 in laptops as early faster AMD cpus got too hot.

Intel Atom 1,6GHz
Intel i3-540 ( FCLGA1156)
AMD C-60 1GHz (Socket FT1, 2011/2012)
AMD A8-3870K

AMD A4-7300 (FM2)
AMD Sempron 2650 (AM1)
AMD A10 8700P
AMD A10-7850K Black Edition (FM2+, 2014)
Intel Core i7-4700MQ
AMD Athlon X4-880K (FM2+, 2016)
AMD Ryzen 3 2200U (FP5)
AMD Ryzen 7 2700x (AM4)

Broadcom BCM2837B0, Cortex-A53 (ARMv8) 64-bit SoC @ 1.4GHz (Raspberry Pi 3B+)
Broadcom BCM2711, Quad core Cortex-A72 (ARM v8) 64-bit SoC @ 1.5GHz (Raspberry Pi 4B)

Yes, I always favour the best one overall; AMD ftw!

I feel bad for those that had a Cyrix CPU. Those has to be one of the all time worst with the lack of a couple instructions which limited certain 3D games. It was so bad that one friend of mine literally crushed it in a pressure bench. :D

EDIT: Had completely forgotten about the FX series, and yes, those and a couple of others throughout the AMDs different lines was and still is a real beast in sheep's clothing. Plenty of times they were buried among all the ones that Intel spew out and almost every time it surprised me how well they actually performed outside of dry benchmarks.

I'd actually expect an 8-core 3.5-4 GHz CPU to run things pretty darn well. It does lack a decade's worth of optimizations and extra features, but in raw power it's still up there, albeit in exchange for twice the power draw of a similar one now. In fact, strictly in terms of cores, the 5600G actually goes down compared to it.

Nice to see everyone's lists so far, it has been a while since i participated but, this post got me out of hiding.

8088XT
intel i7 920
intel xeon x5660
amd ryzen 5 2600
intel i5 10600k

That's fair, but it definitely wasn't very compatible with modern games/software and thus did cause me various issues as time went on.

Yes, the summers were miserable but that heat was very nice in the winter haha. It actually got so hot that my AIO liquid cooler burned up and almost fried the CPU. Decided to go with an air cooler replacement, as they're cheaper and liquid cooling isn't THAT much more effective if you're not dabbling in overclocking.

Way to many but to list the favorites/most used:

Intel Pentium 3 733
Intel Pentium M (laptop)
AMD Turion dual core (laptop)
Intel Core 2 Duo - can't remember the model
Intel atom n450 (laptop)
AMD A4 7400 later replaced by a X4 860k
Intel i5-4460
Intel i5-2520M (laptop)
Intel Atom x5 8350 (tablet)
AMD Ryzen 1600 (AF)
Intel i5-4300u (tablet)
Intel Atom x7 8700 (tablet)
AMD GX420 (Thin client)
Intel Pentium 4415y (tablet)
AMD Custom 0405 (Steam Deck)

Still in use but not on the main list:

AMD Phenom x4 960T unlocked to 6 cores
Intel Core 2 Quad Q6600
Intel i3-7100u (laptop converted to desktop)
Intel i5-8250u (laptop)
Intel i5-1035G4 (tablet)

Edit: Almost forgot: Intel G3258 Anniversary - one of my favorite CPU's ever, overclockable on many 40$ boards. Still have it but can't justify buying a board to build a computer. Was replaced by the i5-4460.

Actually the FX/Athlons CPU's were very, very weak, despite having the number of cores. While they do ok with rendering tasks, playing games were slow as heck.
A similar CPU from Intel at that time (similar in terms of cores and clock speed, not price) was at least twice as fast and used half of the power. The first FX generation was comparable (depending on the tasks) to the previous Phenom CPU's. That doens't mean they couldn't play games just fine and the price was very atractive.

FX/Athlons performed worse than a dual core Intel at the time on popular Minecraft, not only on FPS but also world loading. Games that didn't use the CPU as much were fine I guess and like JakobFel mention, they still run many modern games in a playable manner. But compared to the competition at the time they were hot snails.

Fun fact: FX 8 cores are now considered 4 cores due the weird architecture and a Lawsuit. Most publications now list the FX line with half the original core count but not the Athlons (wich were very similar).

MOS 6510
80286, 12 MHz, 1 MB
80486, 33 MHz, 4 MB
Pentium, 100 MHz, 16 MB
K6, 233 MHz, 64 MB
Ahtlon Thunderbird, 1.1 GHz, 512 MB
Athlon XP 3000+, 2.1 GHz, 2 GB
Core 2 Duo, 3 GHz, 8 GB
i5 3570k, 3,4 GHz, 16 GB
i5 6500, 3.2 GHz, 16 GB
Ryzen 3900X, 3.8 GHz, 64 GB