Tengen Toppa Gurren Lagann, Heartcatch Precure! Recommendations
Although their not similar in content, they are similar in execution and style...
So basically, if Gurren Lagann was a magical girl anime, it would be Heartctach Precure! (And vise-versa.)
-Both have awesome and over-the-top battle sequences.
-Both have the "Determination" thing going on.
-Both play their genres straight, but in a good way.
-Both have simple plots that are executed very well.
-Both have great characters that make you want them to persevere.
-Both share crazy art styles and style of animation.
-Both share very funny comedic moments.
-Both have hot blooded characters in them. (Kamina and Kumojaki respectively.)
-Both have heartwarming moments.
-Both have emphasis on teamwork.
If you liked one you may like the
Both shows play their genre's tropes straight and then some into delicious ridiculousness. They also have many genuinely heartwarming and sad moments despite its otherwise silly tone.
They also share many elements like similar finishers (Especially Fortissimo and Giga Drill), an intense space climax in enormous scale, boiling hot blood, and a main protagonist that breaks out of his/her shell to become one of the coolest characters in the show.
Over the top action scenes and very touching moments despite their solid comedy and exaggerated style. Teamwork, friendship and determination are main themes of these series.
Different settings but in my opinion they can cross the barrier of dislike towards their genres (mecha and magical girl respectively) to be enjoyed by anyone. They also feature an epic climax to their stories that makes them unforgettable.