You are right. Threads are taken off topic and newcomers are simply lost.
We are not allowed to recommend sites but, nevertheless, we are allowed to point out how you may identify the legits from the scammers:
1) Read the webcopy and please focus on the use of English. Is it professional? Well-written? Anything which sounds linguistically incorrect - leave the site ...
2) Price ... of course, any would be tempted to purchase from a cheaper website but ask yourself whether a truly legitimate company which hires truly qualified writers, will accept peanuts as payment? Quality costs and is worth it ... so stay away from the cheap sites.
3) After you've identified the better sites (webcopy and price), contact them through AliveChat and ask for their phone number ... call them up. Does the person on the other end speak good English, etc etc
4) Re - companies which you have shortlisted ... is the company registration number displayed on the website? Are they able to provide you with a company address?
5) A lot of companies operate virtually (nothing wrong in that) and this means that they usually take out voip numbers in several countries (UK, US, etc etc). If you are not able to identify the number you are calling as a VOIP or landline one, ask them for a mobile number. One would assume that members of the management team, not to mention the owners, have cell phones. Now, if the site claims to be British, you should get a UK mobile number ... US, the same, etc etc
6) Importantly ... does the company guarantee confidentiality and does it resell your paper ... you need to clear up these two points.
I am not advocating any particular nationality here but am emphasising legitimacy - a legitimate company does not lie about location, nationality, etc etc. So, make sure that you are not being lied to.
Were you to ask forum members for recommendations, a great many of us would be biased in favour of our own websites/companies. Only a handful here would be objective so, it is best to make the call yourself.
And ... don't worry. Certainly, there are many scammers out there but there really are some excellent companies and websites.