 If you liked Boku wa Tomodachi ga Sukunai |  ...then you might like Masamune-kun no Revenge |
Both anime are harems and rom-coms. Still, Haganai is much funnier and much better than Masamune-kun. Both anime have karaoke scenes, pool/beach episodes, the rich girl, the feminine guy, MC's little sister and fanservice.
report Recommended by nifetiseBOY
Both MCs are getting romantically involved with a childhood friend, and as to not spoil anything I'll leave it at that. Also, both shows have a 'Trap'... kinda. Again, not to spoil anything.
report Recommended by ButadonMeitantei