I have no problems with hyphenated domains, I sold two this year to European buyers as it seems the rest of Europe uses hyphens alot more than the UK or the US. Also there's an interesting section on DomainSherpa this week where they talk extensively about the decreasing value of .Net's.
Me I would also choose .com with a dash if the .com without the dash is undeveloped. If it is developed then I would maybe rather go for a .org then a .net..
Magicpig, you are right, dashes are very common in many countries in europe. I have the same experience and a few smaller sales.
Here is a "surprise" - I am for none too. Of course the .com should be a natural first choice but as you don't own the unhyphenated domain this just means that the hyphenated one can lose a lot of type-in traffic to it (not to mention if they also have trademarks established). Which leaves you with the .net which is...well .net (to an already registered .com, check above for same reasoning).
BUT...if those were the only two domains left in the world and I would have to choose one unless I want to suffer a horrible and painful death then maybe I will go for the .net