Formal:
* Vous me faites rougir. (This is the most literal translation and is appropriate for formal situations.)
Informal:
* Tu me fais rougir. (This is the informal equivalent of the above.)
* Tu me mets la rougeur. (This literally means "you put redness on me" and is a more playful way to say it.)
Romantic:
* Tu me fais rougir de plaisir. (This means "you make me blush with pleasure" and is a more romantic and intimate way to say it.)
Playful:
* Tu me donnes des couleurs. (This literally means "you give me color" and is a fun way to say it.)
The best way to choose the right phrase depends on your relationship with the person you are talking to and the tone you want to convey.