David P. answered 03/25/19
Experienced photographer, cinematographer, actor, and VO talent
In general, the best is the one you have the most experience with. Adobe Premier Pro is one of the standards, and has a wide range of tools, although to get the most out of it you will need to full Adobe Suite. I prefer using Davinci Resolve for video editing, as it has a full range of tools within a single program (including VFX and 3D modeling), and the layout is better suited to my workflow. The downside to Resolve is that it requires a more powerful computer processor (especially working with 4k footage or high frame rates), but it does render more efficiently.
While both programs have audio editing software built in, I prefer Resolve's audio software if I'm mixing audio with the film. Typically though, I still use an outside DAW (I prefer Reaper, but again experience and familiarity with the software plays a huge role). Once in the video editor, I will sync the audio and add any final tweaks to the mix.
In the end though, you can get decent results with cheap/free editing programs so long as you develop a consistent and effective workflow. While there will be limitations, if you know what they are you are better equipped to work around them. Oftentimes, if you are also the one filming, you can plan your shots/lighting/setup to overcome software limitations so long as you aren't working on high budget film.