I'm assuming that my own nomination has to be second, though I'd probably put another character in first anyway.
1. Viewtiful Joe
2. Mike Haggar
Viewtiful Joe was great, and it's a shame that we never got Viewtiful Joe 3.
Job 19:
Lady (Devil May Cry)
One of Dante's allies, Lady stands out among the playable characters in the Devil May Cry series by being the only one with no demonic powers. Instead, she just has guns - lots of guns. Her main weapon is Kalina Ann, a rocket launcher with a bayonet/grappling hook which can be used for slow melee attacks, but she also has grenades, a shotgun, a crossbow, a submachine gun, and twin pistols. In addition, Devil May Cry 5 gives Dante a second rocket launcher called Kalina Ann II, which was intended for Lady - Lady could presumably use both rocket launchers in the same way that Dante did.
Lady's a popular enough character that she became one of Dante's partners going forward, and people were hoping for her to be playable in DMC3's Switch version as one of the new features. For reference for how she could play,
here's her gameplay from Devil May Cry 4.
Hyper Combo ideas:
-Level 1: Biker Ram - hopping on her motorcycle, Lady dashes straight forward - this attack has super armour, but once she travels far enough, she leaps off of the bike and it explodes
-Level 1: Multiple - Lady stands still, aiming her bazooka, as the player controls a cursor that moves around the screen. Pressing the attack button, or after a certain amount of time, causes homing rockets to launch at the opponent - you can have multiple cursors on an enemy character, but waiting it out leaves her wide open to attack
-Level 3: Cascade - Lady pulls out Kalina Ann II, connects the two rocket launchers together, and fires a long-ranged heat beam/laser that pierces through enemies. The laser can be steered upwards or downwards, but it's tough to control like this, and it works better with just firing it straight ahead.