Bleach,Naruto,One Piece,Fairy Tail,Sword Art,Attack on Titans
Totally try em,=!
Those are all mainstream animes, with over 300 episodes besides SAO and AoT.
Try:
Mondaiji-tachi ga isekai kara kuru sou desu yo [overpowered maincharacter]
Ao Haru Ride [romance and a very good one]
Attack on Titan [was already suggested, but this one is really intense
]
Highschool DxD [ecchi, means it has sexual elements in it]
Code Geass [kinda sci-fi and romance, recommend this one]
Nanatsu no Taizai, also known as The Seven Deadly Sins [great anime, plz watch this]
Ao no Excorcist [about the devil and demons, recommended]
Beelzebub [hilarious anime, amazing humor]
Magi [really good anime, it's about magic and has great animation]
Hunter x Hunter [mainstream, but really good. If you have time, watch the other mainstream anime too such as: Naruto, Bleach, Fairy Tail etc]
Kuroko no Basket [basketball anime, amazing animated]
Haikyuu [same as ^ only with volleyball]
Mirrai Nikki [great psychological anime]
If u want more, feel free to contact me
Have fun watching