In Indonesian to say "I LOVE YOU" is "AKU MENCINTAIMU". How about your language?
In Spanish:
Te quiero.
Maybe more romantic:
Te amo.
In Czech it is Miluji Tě.
Я люблю тебя. (Ya liubliu tebia).
Мен сені сүйемін (Men seni suiemin) in Kazakh
我爱你