Should I contribute to RRSP or Non registered?

I earn around 100k a year, have 20k in emergency fund. I have excess cash after paying of credit cards and Mortgage and I also save 500$ to a HISA. I maxed out my TFSA, I have around 30k room in RRSP. I have a trading account for my TFSA. So should I open a RRSP trading account and take advantage of the market and as well as tax returns? Or open a non registered account and save the rrsp room for future?

Thanks