Savings. Who to choose ?

So im looking for a savings account but it might not be worth it so I'm looking for advice.

I want to save, but like everyone I want a good intereset rate.

I don't mind how long for, I want the most potential return.

So if I had €50 a week or €200 a month to put into a savings account where would be the best to go or would it even be worth it for the small amount ?

Also can anyone explain dirt tax in the most simpliest format ?

Thanks all