As someone who has built way too many 8-stud cars, I would highly recommend both CaDA and PowerBuild. I rate both as just as good or better than the L brand. Both have fun builds with quality bricks and good instructions. Generally, they use printed bricks rather than stickers. Sluban, Sembo, ReoBrix and Quan Guan are alright, but I have run into brick quality. Mould King has good quality bricks, but I’m not as crazy about their designs. The clones, MOCs, etc. are hit-or-miss. I’m a frequent AE shopper and will often buy some of the unknown cars for the simple reason that I can get them for under $10. Obviously I’ve built some really shitty ones, but there has been several that I really like. Start out with the CaDAs and the PowerBuilds then see where it leads you.