If you're chasing a fast, foolproof lip-sync pipeline, Adobe Character Animator is the sort of tool that makes me grin every time. It takes a lot of the grunt work out of mouth rigging by using viseme-based puppets and automatic lip-sync from an audio track. You build or import a puppet with mouth swaps or draw a mouth rig, feed it audio, and it maps phonemes to mouth shapes; then you scrub through, tweak the timing, and you already have a very watchable performance.
For projects where I want more control or a cut-out look, Cartoon Animator (by Reallusion) and Moho are huge time-savers. Cartoon Animator has a clever mouth system with pose-based swaps and smart morphs so you can animate subtle expressions without redrawing every frame. Moho's Smart
Bones combined with bone rigs give you smooth jaw movement and secondary motion; it's a great middle ground between hand-drawn flexibility and rig-driven speed. If you like working with meshes and deformations, Live2D (for face rigs) and Spine (for game-ready rigs) are fantastic. Blender also deserves a shout — use shape keys for mouth phonemes and pair them with Rhubarb or Papagayo for phoneme timelines; it’s free and surprisingly powerful once you get the workflow down.
A quick tip I always follow: start with a small set of clear visemes (like A/E/I, O, M, neutral) and get the timing right before adding nuance. Whether you choose swap-based mouths or deformable meshes depends on your style and how much hand-tweaking you want, but these tools will make the rigging stage a lot less painful. Personally, I keep a soft spot for Character Animator when I need speed, and I reach for Moho when I want that craftier, articulated look.