what to use to convert dv videos to some better format

I have about 400 GBytes of videos that are in .dv format. They still open, today, with the current version of Quicktime Player (version 10.5) on macOS 10.15 Catalina but it would seem wise to convert them to some other format that will continue to be supported into the future.

First, what format would folks suggest is best??? .mov. .mp4 what???

And then, what software might you suggest to buy (or find free but I'm willing to buy) that would be the best software to convert these files. Space is NOT my problem. file type support into the future is what I'm looking at.

your thoughts??? thanks...