This discussion is inspired by the subreddit /r/oddlysatisfying. Note this is SFW in this case.
I'll start...
Walking on freshly mowed and cool grass (especially on warm sunny days
Sanding and cutting joints that fit together perfect
When you open a can or bottle of carbonated drink and you see a "fog" come out of the top
Sucking on a Mike and Ike so that you eat the flavoring off and are left with the gelatin core
Taping two pieces of paper side by side and they have a smooth, consistent joint.

This discussion is inspired by the subreddit /r/oddlysatisfying. Note this is SFW in this case.
I'll start...
Walking on freshly mowed and cool grass (especially on warm sunny days
Sanding and cutting joints that fit together perfect
When you open a can or bottle of carbonated drink and you see a "fog" come out of the top
Sucking on a Mike and Ike so that you eat the flavoring off and are left with the gelatin core
Taping two pieces of paper side by side and they have a smooth, consistent joint.

What is a Mike and Ike? 

I wouldn't describe this as oddly satisfying as such, more like plain satisfying but anyway:

You're so tired, exhausted, worn out and go to sleep. You wake up the next day feeling refreshed, energised and revitalised.

It would for me, since every time I wake up, I feel crappy.

@Mercurylamps : A Mike and Ike is a candy, very much like a jelly bean. I've never tasted them so I can't tell you how they taste. I have an old package of them that I use for a chemistry laboratory demonstration where I melt a bit of potassium chlorate to produce a hot environment very rich in oxygen and then drop a Mike and Ike candy and it burns quite spectacularly with a whitish flame. Most teachers use gummy bears but I always fear it won't drop to the bottom of the test tube hence a "dry" candy instead of a sticky one.

Here are some I like:
-Watching mercury vapor and probe start metal halide lamps re-striking
-Installing Ubuntu on old computers
-Replacing ballasts in fixtures, especially when it is like something from HPS to MH or MV to MH.
-Watching things get destroyed while running (this excludes street lights getting taken down by cars) Here is a channel dedicated to this: https://www.youtube.com/user/ssmmkk2

I also like wiring ballasts,fixing transmitters at work,Building electronic kits when they were available,doing the vacuuming at home and work(remember I am one of those vacuum guys),using various appliances,collecting them.I also like that destruction channel-if you like that look up "SSI World,"Komar Industries,ShredTech,"muffin Monster"various shredder and grinder sites.The Elmo dolls getting ground up with the mower and "Drilled" was halarious!There was another destruction site that showed things being smashed with golf clubs-the poster took those down,they were also funny.He also ran over Elmos with a mower and threw them into a fan.

Repairing old computers and other IT equipment. Replacing capacitors, repairing fans, and so on. Then i install Gentoo (previously Arch)

Brand new or smooth concrete
Distant lightning and thunder from an approaching storm
Rain on the roof at night

Here is another one: That refreshing smell when you first turn on the car A/C or window A/C. It has got to be my second favorite smell besides the smell in Subway restaurants. 

Here is another one: That refreshing smell when you first turn on the car A/C or window A/C. It has got to be my second favorite smell besides the smell in Subway restaurants. 

I've always wondered what that actually was.
I always thought it was refrigerant residue.

Quote from: Zarlog on June 02, 2016, 10:53:51 AM

Here is another one: That refreshing smell when you first turn on the car A/C or window A/C. It has got to be my second favorite smell besides the smell in Subway restaurants. 

I've always wondered what that actually was.
I always thought it was refrigerant residue.

It is most likely mold.

Quote from: wattMaster on June 02, 2016, 10:57:55 AM

Quote from: Zarlog on June 02, 2016, 10:53:51 AM

Here is another one: That refreshing smell when you first turn on the car A/C or window A/C. It has got to be my second favorite smell besides the smell in Subway restaurants. 

I've always wondered what that actually was.
I always thought it was refrigerant residue.

It is most likely mold.

Then every air conditioner has mold! 

Maybe not all, but certainly most. The one in my house (a whole house heat pump) usually does not smell but the one in the car always does. The heat in the winter probably kills the mold in the house unit but not in the car. The problem is much more prevalent than you'd think.

Wow, the more you know. Is the mold in the filters (easy ish fix for some) or is it deeper than that? Another thing that remind me of AC is a cat. I was at a friends house and the cat went into a back room and started lapping up the drainage water from the furnace. He told the cat to stop, I'm not sure if this is mold or mildew buildup related or just so the cat doesn't spend 20 mins licking the floor.
Another satisfying thing is using tape without getting hair sticking out of the edge or is underneath it. With the pupper and my dad shedding (roasted), there's hair everywhere, and vacuuming doesn't do much but stir it up.

The mould is probably not much in the filter unless it is never changed, but in the air conduits and in the coil. As for the water, all refrigeration systems will condense water on the cold side. With a heat pump or air conditioner, the cool side has condensation. My heat pump has a drain in the basement for the air conditioning cycle and the outside unit has frost buildup (frozen condensation) during the heating cycle. This would not be the best water for a cat (or any living thing) as it is practically distilled water (deprived of minerals). Of course it has been soiled by the dust and what not in the furnace so I wouldn't use it as such.

Heat pumps will have less mould as the wintertime heating cycle will likely kill it.