The Best of the Best (partially updated December 29, 2022)

If looking to earn tier credits cheaply, your best bet are games with both a high return and low variance. Also, games higher than $1, single-play are preferred, to speed up the process (so it doesn't take 10 hours to earn 2500 tiers!)

Of all the games listed above (ignoring where they are located in the country), here would be my favorites to play for earning tier credits toward Diamond or Seven Stars:

#1 Choice: El Dorado Reno. Lots of games available at 99.54%-99.96% return, with the standard $10/tier credit earning. Silver Legacy in Reno is also good.

#2 Choice: Harrah's Cherokee, Not So Ugly Deuces (99.73%). You can earn tier credits quickly at this $5 machine, and you will only average a $1350 loss getting to Seven Stars with it! There will be some variance due to the $5/credit, but it won't be unbearable. If you can't play this game, the 99.64% Bonus Deluxe at the same casino is also a good choices.