To perform the equal and unequal load balancing in cisco environment which routing protocol is the best?

EIGRP - Cisco Proprietary protocol is the only protocol that can do unequal load balancing, by using Variance command. But by default the variance of1 does equal cost load balancing. So if you want to do unequal cost load balancing you have to configure it manually.

The only protocol that can support unequal cost load balancing is EIGRP. It is cisco proprietary. Other protocols will do equal load balancing. In terms of switching environment. GLBP is the only protocol to support redundancy and same time unequal load balancing. You can read my artical on EIGRP undrr cisco on my website. www.itmag.weebly.com

EIGRP

Enhanced Interior Gateway Routing Protocol 

Ofcourse EIGRP.

Equal load balancing is by default supported by EIGRP and OSPF both protocolos,

While when it comes to unequal load balancing, there is only one protocol EIGRP which supports its, by using the variance command and setting up the backup paths.