I've said it before in another thread and will say it again here, the best way to find a good provider is to ask people around you. There will be people you know, friends and family already using IPTV, ask them if they would recommend their provider, ask if you can look at what they get etc. Friends and family are not going to recommend something they are not happy with.
Googling for the best providers is just pointless, if a provider has been found by google or a 'top 10 iptv' list then that means the authorities can also find them and before long they will get cought and shut down.
The same could happen on a forum to an extent, if you can ask on a forum for a trial, what's stopping Mr B Dick who works for Sky or FACT asking for a trial?
You need to find a provider that you can't find online.