What speed internet do I need?

Family of 2 adults and 1 toddler.

HD video streaming (Netflix, YouTube), gaming (call of duty), basic web browsing, emails.

Would like no buffering (obviously), not too concerned about download speeds on game updates.

Fibre 50/10 or 300/100?

Can save ~20 a month with the slower plan

Any help is appreciated 🙂