The Villna Geon who considered learning Torah to be higher than all other mitzvot.
The Gra held that learning Torah is the highest service towards God.



But I think I should make it clear here my own opinion. I think that the Torah itself is clear that Devekut (attachment) with God is the ultimate goal. And I made a mistake once a long time ago pushing off Devekut in order to learn, and I think that was a serious mistake.
What the Gra issaying here then  is that learning Torah is the most effective means of coming to Devekut. But learning is not some kind of separate goal apart from Devekut.

Appendix
We know that the Gra was simply basing himself on the Jerusalem Talmud in Peah.