TalosSSB
Smash Cadet
Non-bias opinions.
Mario.
Why? Mario has the Drill ability with his Dair allowing him to somewhat spike people, along with a down B spike and down B spike throwing downward at end of his bottom hitbox.
Along with the fact Mario has a very good recovery, Good fast fall time not too slow not too fast, He's middle weight so not too light, but not too heavy to be combo'd easily.
He ALSO has Fireballs, which are a ranged projectiles that you can easily spam across the map by doing Bs in the air instead of doing B on the ground because it takes more frames.
Mario has a good/crazy up smash hitbox and has controllerable Fsmash to upward, and downard and middle fsmash. Along with his Down Smash which hits from front then back so if they roll, you could possibly rely on that.
Mario is the best overall character but when it comes to competitive standards, he seems pretty well fit. I personally feel comfortable using him against any other character including pikachu.