There isn't one universal 'best' brand — the right choice balances performance, warranty and price for your situation. The safest starting point is a Tier-1 manufacturer, a financial-stability ranking that most reputable brands hold.
Compare panels on efficiency (output per square metre), degradation rate (how slowly they lose output), temperature coefficient (performance in heat), and warranty (product and performance years). Newer N-type/TOPCon panels lead on most of these.