In general, the Strip takes a higher percentage. I'd try the Stations properties, the Orleans, Hard Rock, Palms... Fremont St if you like that sort of "ambiance"...

If you have to play on the Strip, higher-denom machines generally have better odds for the player (think dollar or 5 dollar machines, and play them at max, so that you qualify for progressive jackpots, and get the best odds over-all on the game). WHATEVER machine you play, try to max-out the bet every time; you don't want to be the joker that hits 3 Megabucks on the payline, with only one dollar bet!