Also agree with Joseph regarding the risks of sharing names that you don't already own. For me, I'd say wisechat.co is the best. Why? It's two dictionary words, there's no ambiguity when saying it out loud, .co has become as respected as .com. The reason I'm not for crowdsage.com is that 'sage' is not a word used commonly so you could still have to explain it - and you never want to have to explain or spell your domain/email/company name. Same applies to the first two, and wisespace.me is phonetically poor with two 's'. That's IMHO anyway. Happy to discuss in detail over a call. Good luck!