vSphere 4.1 support customization for the following Linux guest operating systems:

RedHat Enterprise Linux (AS/ES) 2.1

RedHat Desktop 3

RedHat Enterprise Linux (AS/ES) 3.0

SUSE Linux Enterprise Server 8

Ubuntu 8.04

Ubuntu 8.10

Debian 4.0

Debian 5.0

So any one of these Linux should be fine to use.