I usually stick to the .com option. Have purchased .net or .org before, but it's usually because the domains had pretty high DR (Domain Rating) and a hefty backlink profile. Otherwise I'll try to either use a dash or find something similar. For my main business, webdesignnj.com, this domain was taken and they'd ask 800 bucks for it, being "premium". I used web-design-nj.com for a while and, when the price dropped to 150, I purchased the desired domain and redirected the one with dashes. I'd have been content without it as well, but it was a good opportunity.