If you liked
Tate no Yuusha no Nariagari
|
...then you might like
Arifureta Shokugyou de Sekai Saikyou
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Both are about the main character being isekai'd to another world along with other people where he is seen as the weakest, he gains powers and becomes strongest. Both also are joined early on by abandoned loli.
If you liked
Rakudai Kishi no Cavalry
|
...then you might like
Gakusen Toshi Asterisk
|
Both are about a guy who goes to a school where people fight each other in matches where they meet a powerful red head who is a tsundere.
If you liked
IS: Infinite Stratos
|
...then you might like
Saijaku Muhai no Bahamut
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Both are about universes with battle armours where there is a male who goes to an all girls school where they learn to fight in these armours. While Saijaku Muhai no Bahamut is set in medieval type era and IS is futuristic. They still have similar vibes and character relationships.
If you liked
Sword Art Online
|
...then you might like
Accel World
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They are both about a school kid who is introduced to a game where they fight. There are even references in Accel World to SAO so they might be connected with Accel World set in the future. They both have a strong male protagonist as well as a strong female character.
If you liked
Death March kara Hajimaru Isekai Kyousoukyoku
|
...then you might like
Isekai wa Smartphone to Tomo ni.
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Both anime's are about a guy travelling to another world and gaining powers that make them OP and then go on a journey across the land while gaining a harem along the way.