Regarding Internet

If you just want fast internet, Mobile Vikings are really good - they use the proximus network, although they are cheaper than Proximus, and if you have fibre to your house you can get a gigabit connection. If you don't, you're limited to 100MB IRC.:

https://mobilevikings.be/en/offer/internet/.

They are fine communicating in English if you prefer not to use FR or NL.

Depends what you mean by best. Cheapest or fastest or most reliable. Best customer service/problem resolution?

I use Proximus. Best connection. Fibre optic cable connection so very fast. Very quick response when calling customer service. And unlimited data. But that comes at a price. I think I pay about €120 a month.

But for that I get superfast unlimited Internet. A landline and a mobile connection, with free unlimited calls and sms to all EU countries (including mobiles), plus Norway and Switzerland,
and USA. I also get a TV connection with 200+ channels, although that mostly used by my mother who only really watches BBC stuff.

The good thing is that so much is included in the package that my telecoms bill rarely exceeds the €120 for the package deal.