I always rely on a Zebra 402 and a Muji gel pen. No leaks so far.
I have these, they don’t leak. They write under water, upside down, under 0 gravity (if you happen to be in space), etc
I’m partial to fountain pens and this is what I use daily. It retracts and clips tip up to help prevent any leaking from the nib. When the tip is pushed out, the little trap door seems to prime the nib for immediate ink flow.
I bought the Fisher Space Pen ‘Bullet’ model in brass for carrying in my pants pocket. I really like the form factor and that it transforms to a full-sized pen. It has developed a beautiful patina.
I was not impressed by the stock ink cartridge. It seemed to create a blob quite often when starting. I found a list of cartridges that can be modified to fit, and ended up with a Zebra refill. I like it much better.
That was a great episode of Seinfeld I’m thinking about re-watching the whole series
I use a Tacray Tc4 titanium pen and a brass bolt action pen that both use the Parker refill’s. I have had them for years now and they both write smooth with no problems in any position.
I have several tactical pens but my favourite ones are the Benchmade 1100 with the blue Fisher space refill.
Definitely check out the Matthew Martin 500 (full-size) titanium screw top. I actually want to get his zirconium pen but it’s sold out everywhere
‘Pilot G-2 07’ Smooth even flow, no leaks, cheap.
I have been using one of these twisty metal pens for quite a while.
It’s also available on AliExpress.
With Parker G2 refill it writes quite nicely. It’s cheap and durable. I don’t want a “tacticool” pen but I love this one for its durability and tough pocket clip, it’s actually tougher than my flashlight’s pocket clip.
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I used to carry Zebra F-701 but it’s not durable enough, pocket clip always broke. Also, this Aluminum Alloy Ballpoint pen with Parker G2 refill writes nicer than Zebra F-701.
I have had another metal pen with bolt action mechanism which I also liked very much (also takes Parker G2 refill), been using it for a few years. Then I gave it to a friend of mine.
I still love bolt action pen but this new one with twisty mechanism is cleaner without protruding thumb stud, very practical, IMO.
I still love bolt action mechanism very much though and been considering to buy another one.
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It’s about USD 1.5 on AliExpress :
Aluminum Alloy EDC Ballpoint Pen
https://www.aliexpress.com/item/4000558245340.html
(no affiliate, that link is just an example, I didn’t even buy it from that link, I bought it from local online store, exact same item though 
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I also have some Uniball Jetstreams and I like them (black, red, blue), they write very nicely with stock refill . Not pocket EDC though, not tough enough.
Also some Zebra F-701’s which aren’t tough enough (broken clips) 
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For full-time pocket EDC : twisty or bolt-action mechanism is the most ideal, IME.
My bolt-action pen was similar to this one :
Bolt-action pen on AliExpress :
With smooth body it’s rather slippery to hold and write with, IME.
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I think this one with some knurling is better :
Another bolt-action pen on AliExpress :
Sorry for OTT a bit , Back to topic : Uniball Jetstream.
I never have a leak on any Uniball Jetstreams that I have. They write very nicely, better than some Zebra’s and Pilot’s ballpoint pens that I have. About the “Uniball”, I think I read somewhere that it’s a kinda hybrid between ballpoint and gel pen (???) , I don’t know , I’m not a pen-expert .
I love ballpoint and hate gel pen.
Uniball Jetstream no failure IME.
I also have Pilot G2. I very much prefer Uniball Jetstream.
Carrying my black zero tolerance tactical pen with tungsten carbide tip. I’ve had this thing for years! Fortunately I’ve only every had to use it to write with (:
“Anybody use these pens?”
i do not know the names of the free ones i use.
“Do they leak?”
i would bet yes, but again, i cannot confirm.
Pilot G2 is about the best gel pen I’ve found, too. I was using some Papermate Inkjoys, Forays and Callistos, but they have erratic output or (in the case of Inkjoy) are hard to get started. I haven’t had leaking problems with any of them, though.
Okay, I've done some significant research since I started this thread. I bought a whole bunch of different gel pens. I went all-paper with my note-taking. I found excuses to write letters, sketch diagrams for projects, etc. I went pen-crazy and even got some friends and family in on the excitement. The ultimate winner for its refill is the Pentel Energel in 0.7mm. I rather like the needle tip but the conical tip is good too. It writes wonderfully and is stable for EDC. (S-Gel was the runner up but had some quirks.)
The only hitch is that I didn't like the Energel body. Luckily, the Energel refill fits into a ton of other pens. For a clicky pen, the Zebra Sarasa Clip has a nice cheap donor body. (The Sarasa Clip is compatible with the S-Gel spring for this and other refills if you want a little more pep in the action.) Looking specifically at EDC pens that'll use this refill, the Pentel Philography has a classy twist-action body. The OHTO Liberty is a classy capped pen. It doesn't post but that's okay. I also really like the Pentel Hexreform but it's an Asian exclusive. I tracked one down on AliExpress for $28. That's the most I've ever spent on a pen but it's fantastic.
Thanks so much for sharing your experience. I love pens too .
Zebra Sarasa is one of my favorites.
Now you’ve got me interested in Pentel Energel.
My favorite pen is the Uni Power Tank 1.0
I need to try the Uni Power Tank .7