Oddly enough there isn't as much variability or even consistency as you might believe in terms of slot theo. Still you would be better off playing a full pay VP game 4x longer to get the same theo with a lower expected loss. (i.e., play $1,500 coin-in at VP instead of $300 coin-in at slots and you'll get around $30 in theo at VP and around $24 in theo at Slots but with VP you'll have an expected loss of around $15 versus $24 at Slots thus you save $9 bucks.
If you are determined to just play slots to look stupid your best bet is probably Double Diamond $5 denomination which will be around 94% payback but also low variance (in terms of slots).
Why not just slow play roulette with a Max Rubin comp strategy betting $500 per spin betting mostly red numbers inside and loosely offsetting with black bets on the outside and a few small bets on the Green courtesy line. Each spin you'll mostly break-even or lose a little bit but will have a huge avg bet. After 10-15 minutes trim your bet by 30 to 50% when the pit isn't looking and when he returns pump up one spin with a much higher bet than your original rating then trim back immediately to your original bet and then when the pit walks off cut your bet by half as long as you can. After an hour or so quit. If you can manage to manufacture at least a $1000 loss with ratholing and actual loss you should get nice offers in the mail for a long time.