Which the best IP 10.0.0.1 or 192.168.20.1 for local network?!

RFC 1918 indicates that the classes intended for private use are 192.168.0.0/16, 172.16.0.0/12 10.0.0.0/8. This means that if you want a /24 network you can use any of these.. eg. you could also use a 10.100.50.0/24 class