First I know it’s been said, but to clear things up, in Spanish, you use te amo ONLY IF YOU ARE ROMANTICALLY INVOLVED with someone. Te quiero is for everyone. In addition you can use Te adoro.
And for the dialects that use usted only or where usted is used between family members:
Os quiero (a vos not vosotros)
Voseo as used in the Americas uses te.
ámoo/ámoa (with vostede the usted of Galician)
ámote (like Galician)
Ic lufe þē./Ic þē lufe. (each loo-vay thay/each thay loo-vay) 1. the th is like thin not they. 2. the ē in þē is a long vowel to be held out longer. It translates to I love thee or I thee love. (kind of like I thee wed.)
I wanted to add more, but unfortunately, the smaller languages don’t have a lot of information on them, so here you go, hope you enjoy.
And an English to English translation would be, well to more “grammatically correct” English: I love you is I love thee.
There you have it some more ways to say I love you. Enjoy.