In our main brokerage account, we use 6 ETFs:
VONE - Russell 100 index. Why? Started with it in 2013 based on recommendation to get some mid-cap exposure. It essentially tracks the VOO or VTI but it was too late to change it without severe tax consequences. LOL!
VONG
IGM
VTV
VIG
VB
VOO/IVV is a no-brainer. I use them in most accounts. Also, we use the fund equivalent of VTI in our daughter's 529.
As for funds, my go-to are FDGRX, PRWCX/TRAIX, and DODGX. Unfortunately, the first two are closed to new investors, but I think you can gain access to them if you have a large enough account on Fidelity or T. Rowe. Just make sure to use funds in tax-deferred accounts due to taxable distributions.