Best Free Video Convertor?

Have just found 3 dvd’s worth of clip videos dated 1997-2003.
Anyone suggest the best software to use to convert them for viewing on android mobiles?
I’ve got Sage’s ‘undaground’ copied straight over… but format on the rest are given me problems?

I always use Xmedia recode.

handbrake works best for me, it has presets for most major platforms.

Thanks. I’ll give them both a go.