I'm a fan of the greek overhand and what it does.
Just my preference, but I like the short, fast whip motion you can achieve with 'no-windup' throws.
Other than the fig. 8, the G.O. is my best style for accuracy and distance.
My sling is about 2 1/2 ft, 30in, and I can clear a baseball diamond's back fence almost always using the greek overhand and just regular stones. (i.e. slinging home runs.
)
If you're interested in more range, this link
http://slinging.org/forum/YaBB.pl?board=1;action=display;num=1123365044shows a good vid.
Note how he lets the sling drop a bit before he whips it by his side. Also, he doesn't just sling out to the side, it's also thrown a bit upwards, getting a touch of backspin.
Of course, you might be already doing this, and don't have any issues, in which case I will proceed to stop monotoning and make way for my betters.