I prefer duplex slide rules (they have scales on both sides), as these give a wider range of calculations you can perform. Two of the models I personally like are the Post 1460 VersaLog, and the K&E 4081-3 Log-Log-Duplex-Decitrig (that one is fun to say). Specifically the older models that are made on mahogany coated with celluloid. Also there are various Pickett slide rules that are painted aluminum, these work really well too (I like the Pickett N-600 as a pocket slide rule).

I also have a Faber-Castell 2/83n, I believe this model is Cliff Stoll's favorite one, however I find it a bit too busy for my aging eyes. It is really pretty to look at though.

Too bad there isn't a big enough market for someone to make high quality replicas of classic slide rules, with modern machining techniques. I'd really like to see some laser etched metal rules.

I came in here to mention vernier calipers, I've gotten instant respect out of more than one machinist when I pulled them out instead of the digital calipers. They're fun to use too.

Here they still make circular slide rules:

https://www.sliderule.tokyo/products/list.php?category_id=30

At $1200 for one of the cheapest ones... I think I'd rather buy used...

That's actually JPY not USD. Just noticed that when you visit the link on mobile, it shows a dollar sign instead of a yen sign.

And if you don't want to order directly from Japan, you can search for search on Amazon, here is one for 20 bucks: https://www.amazon.com/Concise-Ruler-Circular-Slide-100973/d...

There are a ton of used ones, many in near New or old stock condition, on ebay.

K&E Deci-Trig, or a Deci-Lon if you want something with a few more scales than that one. Those both give you the CF / DF "folded" scales, which are handy.

I'd recommend an Aristo 868 if not a Breitling Navitimer.