My best experience in ED was returning to the bubble to cash in my data following a loop around the core. That sentence alone makes it seem a mundane task but there was a little more to it.
When I started the game I promised myself I would re-earn my Acornsoft badge (see my avatar pic), earned for reaching Elite in the original game. IIRC you had to do it within the first year, & send off a postcard (included in the box) with a code the game supplied.
I started on 13th Jan 2015, and by August was Combat Elite, so I gave myself a stretch target of reaching Triple Elite before the 13th Jan 2016.
By Mid December 2015 I got my Trade Elite & was about half way through Pioneer for Exploration. I had time for one big trip, needed a little over 40mCr and on a previous trip to SagA* I'd earned 30m (mostly honking & scooping) so I knew what it was going to take, and roughly how long it would take.
With hindsight I didn't have to go to such extremes, but I wanted the fastest ship in the game, just to make sure I could get back from wherever I went in time.
I looped around the outer core (the really bright bit), mostly searching for black holes and O&B class stars until I realised that I wasn't sure how much cash I'd earned & if it wasn't enough I needed to allow time for another trip, so I called a friend for help. It's the only time in my ED 'career' I've ever felt I couldn't do something alone, but a lot was riding on this, I had to make it back in one piece, I had to have enough and I couldn't wait.
I was in a 40ly Conda with a 1d distro & a 3a PP. No weapons, minimal shield, fastest ship in the game (this was before engineers) If I got attacked by a single NPC there would be nothing I could do but put four pips to shields & wait for the FSD to charge.
I needed a wingmate. Considering what I had riding on that trip I wanted an armarda but I have a few PvP buddies & one agreed to fly out to an agreed rendezvous system outside the bubble, in a fully equipped PvP Python.
I travelled 10,000ly in the time it took for him to get his solid hunk of metal out to meet me, I'm pretty sure it's the only time I've ever impressed a PvPer with just how much ground it was possible to cover.
We met up in supercruise, winged up & jumped into the destination system where I had left my gunrunner Cobra MkIII (the other fastest ship in the game, weaponless but unkillable) & travelled the most uneventful 500ls, sweat literally pouring off my brow, my wingmate wondering what all the fuss was about
I made it into dock, switched ships & bid my buddy thanks & farewell as I left his Python far behind.
I got the Triple Elite within a year, with a week to spare. As best experiences go I imagine I'm unlikely to top that.
Best experience in Elite
Same... My first experiances where the best, I recal trading in my Viper Mk4... working towards individual module upgrades until it was a superior machine, then using it to earn the cash needed for a type 6, then using that to get an AspX.. Once i got the AspX the Galaxy opened up to me when distances suddenly become less of a barrier.By far, the best experience I've had, in ED, was the months I spent scraping a living in a Cobra while trying to upgrade an AspX to make it mission-capable, back before the credit flood.
I genuinely feel sorry for newer players who will never have the experience of having to think carefully about what ships/modules to buy.