If I want to just enjoy myself on a random trip to a casino with the hope of, on average, breaking even or better (not trying to earn a living playing blackjack here), what basic counting system would you recommend?

I know basic strategy cold. I have attempted Hi-Lo (without too much practice going in), and I usually keep the count about half the time, reverting to simple basic strategy and minimum flat bets as soon as I lose it (or if I'm feeling tipsy or chatting with friends or whatever).

I would be interested in an extremely simple system such as OPP or Aces/Fives. On this forum, I see nothing but complete bashing of OPP, but every time it's being bashed it's being compared against Hi-Lo or KO, and often with the use of indices. That's great if you're an advantage player, but for someone that just wants to pretend they are playing a game of skill whenever they happen to, on a rare occasion, be gambling at the casino, is OPP really that bad? I'm the type of guy that the only two casino games I'll even play are Craps and Blackjack, and the only reason I'll play craps is because I won big the very first time I played. I simply don't like playing games where I know the house has an edge, even if it's the slimmest option in the casino... if I know I can make very simple modifications to my game to take the edge away. Yes, gambling is entertainment, but why not NOT lose money while being entertained?

Please don't compare OPP to Hi-Lo or REKO or anything like that, especially if you compare outcomes with the use of indices. How does OPP compare against Basic Strategy or a simple strategy such as Aces/Fives? Assuming I can eliminate the house edge, what betting variation do I need to employ to have even the most minuscule of advantages?

Otherwise, the plan would be starting my count at +6, increasing bets at +12 and above with a total bet variation between 1 and 5 units, and taking insurance at +18 and above, pretty much as outlined in the original OPP article from the early 2000s by Carlos Zilzer.