Oh, for sure Pay the Rent. The acrimony towards the game has been around for nearly its whole run.
Lucky $even tends to get a fair bit of dislike as well, particularly in recent years, since it's got a reputation for using some really tough setups (like the $19,987 one just this week).
But then again, the contestant actually won with that setup, so it can bring a sense of accomplishment when you "slay the dragon", and actually it seems like this game is actually being won a bit more often compared to a few years ago. I'd just wish there would be more cars in the $25,000-$35,000 range being offered, since the challenge would be a bit tougher yet with a higher reward, and this includes the popular small crossover SUV segment as well. I've always seen the game as a bit tricky, but winnable if you know how to play.
Pay The Rent unfortunately is something I wouldn't mind, since there are WAY too many bailouts and the purpose of most games is to either go big or go home with nothing. People just don't understand the strategy in terms of ordering the first three levels of items. Temptation is also getting bailout overkill as well.
Among the quickies, I'd say Magic #. The range in price of being winnable has gotten wider, yet it doesn't seem like that many more people win, and are afraid to go higher than $1999.