Raghupati Raghav Raja Ram was favourite song of Mahatama Gandhi, he made famous his own version of this Bhajan and sang during Dandi March in 1941.

Here are Lyrics of that Song of Mahatma Gandhi Version:

The version popularized by Mahatma Gandhi:

रघुपति राघव राजाराम, पतित पावन सीताराम
सीताराम सीताराम, भज प्यारे तू सीताराम
ईश्वर अल्लाह तेरो नाम, सब को सन्मति दे भगवान


Now written in English Script:

raghupati raaghav raajaaraam,
patit paavan sitaram
siitaaraam, sitaram,
bhaj pyaare tu sitaram
iishvar allaah tero naam,
sab ko sanmati de bhagavaan


Below I have video of this song from "Gandhi My Father" movie, I liked this version of the song and hence sharing here:
[youtube=580,350]sz7S5IBmtAs[/youtube]