Best place to buy car seats from and car seat recommendations

Where’s the best place to buy car seats from ? Target ? Amazon ? Buybuy baby ? Somewhere else? Baby’s r us is no longer an option and I need to buy two new ones. Help please !

Bonus question what’s your favorite brand and why ? I had Gracie click connect when my son was a baby didn’t love it. We now have safety first and also britax convertible seats and I’m not a fan of those either. The safety first is hard to install I never feel like it’s secure and the britax recently started to have issues clicking the harness in 😮

So I need a new convertible car seat as well as an infant one for baby girl due soon.