Summoners War: Chronicles

These are good monsters to grow early on.
3s&4s all monsters are 5s backwards compatible, but 5s is expensive to grow.

anyway! 

You just have to grow the monsters you like :D

but, more important are their levels(& skills, evolve, awaken..) and runes.

-----------------
fire 3s : fairy(!), Gore(tear glands cave)  
fire 4s : anne(!!), Epikion Priest(!!), penguin knight(pvp) > Harpu(pvp)

water 3s : garuda(!!) >> Frankenstein(pvp)
water 4s : Howl(!!) > Amazon(pve) > Warewolf(pvp, pve)

wind 3s : Pixie(!!)
wins 4s : penguin knight(!!), Mystic Witch(!), Martial Cat(pvp, pve), Griffon(after PC lv60 !!)

light 3s : Garuda(!!), Living Armor(pvp)
light 4s : Epikion Priest(!!) >> Mystic Witch(!) > Amazon(only pve(boss)) > Vagabond(pvp)

dark 3s : Harpy(!!), Fairy(pvp), Hellhound(pvp)
dark 4s : Cow Girl(!!), Inugami(!), harg(!)