What's the best and simplest available ?

Used windows moviemaker but want something that has more, can do more ....as myself and an 11yo will be using it.

Needs to be easy and clear to operate with good effects range.

Or do you have to buy effects separately? If so....any recommendations?

Not for Apple.

TA

Cyberlink gets the best reviews. We use it.

Most people still seem to use Adobe, but has reputation as difficult to use

Does not seem much wrong with the Sony software.

Why not try one of the freebies like Wondershare? It has a watermark but can be bought off. Not expensive.

Sony Vegas and Adobe Premiere Pro are what I use. Now trying out DaVinci Resolve (free). Looks promising.

Are they relatively easy to use ....11yo remember ... and me

As regards simplified movie making and editing software, there isn`t any.

MS Movie Maker and others like that will create films with the very basics for editing, may be OK for uploaded and viewing on YouTube, but to give it those professional finishing touches such as, speeds FPS, audio sync, stabilization, volume enhancements, colour, brightness, contrast correctness, direct stream copying or full processing modes and conversions into certain formats, it requires more specialist knowledge and advanced software.

I have my favourite film creating and editing software and so will other people, depends on what suits each person, but the skills come from your own experimentation and experience.

I've used Sony Vegas before, which is quite good, but it's not free.
If you're using a GoPro camera, they have they're own free software downloadable from their website. The GoPro software has some restrictions for clips from a non-GoPro camera eg cutting of clips is not allowed, but you can get around that by cutting them in eg Avidemux first.