Moving to: m/AskMbin!

As a, primarily mobile developer, my own MacBook Air (MBA) and it's the M2 version.

I do get provided with MacBook Pros (MBP) for work but there's always that advice of separating your own stuff from work stuff. And I wanted to start doing my own stuff and experimenting with beta stuff and the like without messing up the stable dev environment for work. Even though I did consider shelling out for the MBP for more power, I think I valued portability more and the MBA was just way lighter and so far, all the stuff I'm tinkering with are relatively light weight or the M2 just handles it just fine.

Also the act of switching hardware physically gives me a good separation of life/hobby from work, especially not having access to my work code and environment which gives a bit of anxiety, just like the aura of being around work doesn't make me relaxed.

Everyone toying with system level stuff on ARM devices should have a cheap but Linux mainline capable board. Like a classic Allwinner A64 based board.

I don't think I have anything that's worthy of the "pinnacle" award, so I'll go with most niche & prized: a hand powered tubular key cutter, the HPC Pocket Cut-up.

It's a mini (roughly measuring tape sized) hand powered all-in-one cutter+jig that can cut tubular key blanks to any code. Any professional would probably get an electric machine instead, so I'm not really sure who needs the pocket version. The small size makes sense for someone who doesn't cut keys for a living, but the price is ~$300 usd. I found it useful for replicating the service key to my apartment laundry machine, which gives access to the hidden start cycle button which normally only presses when you pay via the coin slide. The hand cutter has standard cut depths already set so all you need to do is pick the lock with a cheap impressioning tool and measure the tool once the lock opens to retrieve the key code, which is easily translated from caliper measurements to key code via publicly available lookup tables.

At ~$300 I may have saved some money over just paying since our laundry is $5 per load and I've used the replicated key for over 5 years (back of napkin math says as long as I've done laundry more than once a month I saved money, not a high bar to clear). I could have done it much cheaper by ordering custom keys online, but being able to cut a different code in 10 minutes if I got the measurements wrong proved to be really useful.

Photography. You'll probably get a variety of answers, but I would venture that a fast, professional level prime (L lenses for us Canon shooters) would be the top vote.

Not the pinnacle, but I am super excited about the Loos tension gauge I just got today. It will help me accurately dial in my sailboat's standing rigging for performance instead of just eyeballing it

There's no real pinnacle for cycling as there are too many disciplines and brands, but what was eye opening for a beginner was the price.

It's often noted that the price to performance ratio just about levels out at $3,500 for a bike (top end carbon frame and wheels with a 105 groupset for example); anything above that is really for people being paid to race. That doesn't stop people with money burning a hole in their pocket from spending 5-12k on a bike thinking the 60 seconds it will shave over an hour long ride is somehow worth it.

Throw in shoes, helmet, bib shorts/shirt ($300 each) and you're looking at one expensive hobby.

Meanwhile most beginners are out there looking for a sub $1k bike wondering why there's nothing available.

I guess two sets of cards but honestly I was never big on Pinochle,

I have an old Miata I enjoy throwing money at. For Miata enthusiasts, it's absolutely owning an OEM hard top.

Might well be this one:
Repurposing an Accom Axial Control Panel
as it combines my previous career in TV, my lifelong interest in programming, my nostalgic tendencies, and my sheer love of buttons galore!
(Work in progress, full write-up is here.)