Look at my recent posts in the New Game Journal for one example of breakitude (though to be fair, FFVIII basically cries out to be broken and abused like a masochist with Stockholm Syndrome).
Meanwhile, I went and abused Pickpocket and Counterfeiting in SO2 until I had a party of level 100 characters before the tournament. Then I realized that from here to Nede was nothing but unwinnable boss fights and non-gameplay related bullshit and that in the time I spent grinding myself up to 100 I could've used to have beaten the game. It wasn't worth it. :negative:
Dragon Quest V. Getting a Slime Knight and abusing the first available casino until you win two Metal King Swords (the whip is not worth it since the only character who can make good use of it leaves shortly thereafter). Suddenly, I'm able to steamroll everything prior to the second timeskip without breaking a sweat.
Dragon Quest IV. Kitting out your party in Metal King Shields and Meteorite Armbands, abusing Taloon's inventory and finances by loading up on Swords of Destructions to sell off at the start of chapter 5.
Abusing the integer overload bug in Secret of Evermore to have nearly capped Def and eventually Att.
And others I don't care to recall at this particular point of time.
Edit: One other I care to recall at this particular point of time are the SRW OG GBA games. Dumping all of your money into a machine gun or two and maxing them out will let you steamroll the earlier parts of the game due to their high availability, low cost to upgrade, high amounts of ammo, decent accuracy and critical ratings, not crippled by crap like water or beam coats, and can be passed around to any real robot in need of a good finisher/boss killer attack or a crutch to help them catch up in levels or kill count for secrets.