2 WANS
Main Wan (Wan1) 10mbps DL - 1mbps UL (this is the main wan because it has a better stability)
Secondary WAN (Wan2) 25mbps - 4mbps UL (this is the 2nd wan because i encounter a random restart of ISP provider..)

online games are priority to WAN 1.
online games will only use the WAN 2 if WAN 1 is down.

Wan 2 will be use for Web browsing (Mail, Youtube, google)
Web Browsing will only use WAN 1, if Wan2 is down.

Note: im just new to mikrotik. kindly indicate a link of tutorial for your load balancing / Fail over suggested method.
thank you very much.

For simple "how to use two WANs" check this. The rest is just a matter of how you mark routing.

ding!