Here's a list of what i feel :
Lucario
Zoroark
Rotom
All the pseudo-legendaries ( Garchomp , tyranitar , dragonite-one of the biggest , salamence , metagross , hydreigon and also Slaking- due to the higher stats it has )
Maybe for some people the over evolved pokemon ( dusknoir , rhyperior , magmortar , electivire , kingdra )
Milotic ( Due to the difficulty in getting a feebas and evolving it many feel it is a legendary )
Volcarona ( Really good stats and rare type combo + difficult level to evolve )
Arcanine And Gyarados ( Due to arcanine being the non-legandary and non pseudo with the highest stats it has been considered as almost a legandary and many do take him as one )-(Gyarados due to the shiny/red gyarados appearance it has been debated as a legendary , also due to the difficulty in raising a magikarp)