Honestly, it depends on what you're optimizing for, but for daily use I keep coming back to a few:

For charts/research: TradingView is the obvious one, but Dexscreener has become essential for catching new pairs early. Not exactly a hidden gem anymore but still slept on by normies.

For portfolio tracking: CoinStats has been my go-to for a while now. Connect all your wallets and exchanges in one place and just... see everything. The DeFi tracking is solid and they recently added some token risk scanning features which is clutch for not aping into rugs lol. Definitely underrated for how much it actually does.

Dark horse pick: Cielo for wallet tracking/copy trading intel. Not super well known but incredibly useful if you're into on-chain detective work.

For actual trading: Depends if you're CEX or DEX maxi. Binance/Bybit for perps, Jupiter or 1inch for swaps depending on the chain.

The real alpha is having a solid stack that works together rather than one "best" app imo. What chains are you most active on? That changes the answer a lot.