My friend and I making our pure potting alchemist way back in the day on Ragnarok Online.
Background: In RO, making potions was a big deal for guild vs. guild castle warfare, the ultimate endgame activity. Pots could be spammed freely in that game, and needed to be, as castles were defended by laying tons of AoE damage on the entrance (precasting.) Attackers needed to disrupt the defense and establish a foothold while spamming hundreds of potions. How many pots you could carry was limited by their weight. But alchemists could make condensed potions, which weighed about a fifth of normal potions. Making a certain number in a row also gave you ranking points, and potions made by the top ten chemists ranked by points healed 50% more. The rankings were very competitive. Because points were awarded for streaks, your average points per x number of pots went up exponentially as your success rate went up linearly. Ie, once your success rate is near the top, every tenth of a percent more has a huge impact. Every point of dex, luk, or int increased your success rate by a certain amount.
My friend and I spent a couple weeks on and off researching all the random, obscure items in the game to maximize our stats. Some of these things were almost impossible to get because no one used them, so no one hunted them, but we ended up getting everything. Also, our guild had an item called Mjolnir, one of only 2-3 on the server at the time, that was ridic powerful for this sort of thing. We leeched (put the character in a shared exp party, since it had no damage stats, and thus couldn't level itself) the character to level 90 on a map that literally no one used because they thought spawn nerfs had ruined it--but we had it to ourselves, so it was great. Then we took the character to get 99 in Bio3, a map where traditionally, 10-12-man parties would camp out in corners, dragging and killing powerful monsters. We did something similar... except we only got 2-3 other people. She and I played 3 or 4 characters apiece, simultaneously, on a map that was considered to be the most dangerous one in the game at that time. With the reaction times needed, alt-tabbing to the wrong client by mistake could potentially get the whole party wiped. But we did it.
With the chemist at max level with the best gear and perfectly optimized stats, we... weren't ready yet. First we had to 99 another character, a very specialized support character that had to be built specifically around the alchemist's build to get the most out of it (MC gypsy, for those who've played RO.) So we did that too.
Then we started making potions. The rankings had existed for a year, and points were never wiped, so we needed to accrue more points than the #10 had since then for our pots to be worth anything. We were pretty rich, but the initial investment drained everything we had, and it took over a week of potting all day, every day. But she and I did it. Finally on the list, we sold our potions at cost to our alliance, bought more mats, and shot up to #2. No one could touch us... except #1, the potter for the enemy alliance.
But as it turned out in a huge scandal a couple years later, the only reason they could maintain that spot was because their guild leader's girlfriend was a GM who used her powers to secretly create items for the guild, including an endless supply of potion mats. A disgruntled member of that guild posted proof of all this, and all the top figures were permabanned. Our guild had been founded years before by someone who'd been backstabbed by that guild leader with the express goal of defeating them until they disbanded. When that actually happened, we all half-joked we'd beaten the game. The alchemist, iMacro, was my proudest gaming achievement, and we did our part to win the day.