Planet13... I'm honored that I made your list and sorry not to get to this sooner, but you've gotten lots of good advice. I think the answer may depend on your long term aspirations.
Long term... I would avoid hyphens in domain names whenever possible, largely for reasons martinibuster describes, and also for the usability issues. I'm actually surprised that at this stage in the game anyone would consider a domain with two hyphens as anything but obviously spammy, and even a single hyphen has big limitations.
In general, I would not rely on hyphens to help me rank. Once upon a time, hyphens did effectively add keyword value, as the hyphens were treated as delimiters, whereas keyword1keyword2keyword3 was a text string, not parsed by the engines. The anchor text value came from the anchor text suggested by these domains.
The keywords in exact match domains and partial match domains can help rank for those keywords. They're also limiting, and I think it's extremely likely that their effects will diminish. Building a brand name without keywords is an ideal long term goal... but you really do have to market that name and associate the name with the market area. It helps if there's an existing business.
If you're selling cheap widgets and can develop a great site around this name, having cheapwidgets.tld as a domain name is likely to help significantly and might possibly become a major brand. By contrast, cheap-widgets.tld isn't going to look or sound major.
The branding potential of three keywords strung together depends in large part, I feel, on how they sound when read aloud. If there's a lilt, there might be possibilities.
If I were going for a keyword1keyword2keyword3 strategy, I would go for, say, an exact match unhyphenated .net over a hyphenated .com. If you use the .net, definitely check out what kind of competition the .com might eventually offer.
If I were building a catchy brand name type site, without keywords, I'd want the .com (and the .net etc for brand protection). Ending with a .me or a .it or some ccTLD that spells something cute can get tricky, as Google, I feel, would like to geo-locate ccTLDs.
It's often the case, I've noticed, that hyphenated keyword .coms are cheaper... maybe the only affordable emd .coms available. I feel that the liability of the hyphen is essentially why.
If I owned both hyphenated and unhyphenated, I'd use the unhyphenated and 301 the hyphenated version (for brand protection)... but I would would definitely not promote the hyphenated version to get the separated keywords in the anchor text and then redirect it to the unhyphenated version.
I think that dipper nails one of the big liabilities of a hyphenated anchor text domain, btw, which is that lowering the anchor text repetition in domain name links to hyphenated domains is in fact difficult.
I've seen some single word domains absolutely trashed because of overlinking. I'd keep in mind that Google is increasingly going to value brand recognition over opportunistic keywords, and that there really isn't a short term strategy any more, so you'd best keep the long term in mind.