I'm a big fan of golf, both real and virtual. The best iPhone golf game I've yet found is Tiger Woods PGA Tour, from EA. At $10, it's not cheap, but it is fun. It does, however, suffer from one fairly annoying problem: it's way too easy in its default mode. As an example, here are the final results from a four-round tournament at St. Andrews:
Per round, my average score (my player's first name is Wheat) was 15.25 under par, which is simply unbelievable. Look at second place--14 under par for four rounds, or worse than I do for one round! At about 3.5 strokes under par per round, however, the second place score is much more realistic.
So what's the problem? The problem is that TW for the iPhone includes both a caddy and a putt preview feature. Combined, those two features making putting the ball ridiculously easy. Here's how to use those two features together to crush the PGA events in Tiger Woods.
First, get the ball on the the green in two (for a par 4). It doesn't matter where, really, just get it on the green. There is a length limit, but it's way up there, like over 30 yards away.
Once on the green, the caddy displays messages about the putt's line: "Aim 2.5 feet short and 6 inches left." There's also a grid on the green, marked in square yards. Using the target view, it's fairly simple to place the putt line exactly where the caddy says. Then you tap the putt preview button, which shows you exactly where the putt will go!
If the preview shows the putt in the hole, you're done--just swing at 100%, and the putt will go in, every single time. If the preview is slightly off line, you have to make a slight adjustment, and then can't use putt preview again. Still, every time I made an adjustment, I was able to get the putt to drop.
There's literally no chance you can miss doing this--I was sinking putts from over 60' with regularity, and had maybe only two or three two-putts per round.
To make the game much more fun, turn off the caddy in prefs (you can't disable putt preview, though can opt not to use it). Without the caddy telling you exactly where to hit, it's much much tougher to get the line right, and you won't make 100% of the putts.