What would be the best openings for 100 - 800 rated players?

The Counterplay happens when the KNIGHT takes f7:

So your genius strategy is to hope that your opponent blunders? Do you even chess bro?

It's bold to assume that players below 800 will even be able to get to that point

one trick openings that rely on memorization shouldn't be what you're playing when you've just started playing chess

Nxf7 forks the Queen and Rook. For Beginners, it seems like the better option than Bxf7

I usually do scotch because it challenges black

Ah good question.. I'd say mix it up with every single opening out there.. good or bad.. don't stick to one thing all the time.. 

This will grow your experience fast . Always ask yourself why you are playing a move and when you see your opponents response ask yourself why they played that move.. simple stuff.

That said you should eventually figure out what you like most and that's the best recommendation you will get. 

Otherwise I propose 1.e4 with white 

Against e5 I would advise the Ruy Lopez 

1.e4 e5 

2.Nf3 Nc6 

3.Bb5  ...( almost any move)

4.Bxc6    

This way you eliminate a big major weakness for beginners . One of your opponents knights Wich are very confusing to beginners. In fact a knight is often like having an extra queen against a newbie. And this knight also did a good job. Hence the suggestion

As black try the French. It keeps your king safer than any other opening .. since most of your fellow beginner players are taught the Italian 3.Bc4 move , they tend to always play it when they can.. the French pawn going to e6 on move one blunts that diagonal so your king is fortified

It's funny, at the higher levels, I don't know if I'd say that the French keeps your king safer than any other opening. At the lower levels, though, I feel like I agree with TheMsquare, players just don't know how to generate an attack yet.

Danish Gambit for white, Scandinavian ,Kings Indian ,traxlor n Rousea