After starting VMware Tools installation you may get error: path to gcc is not valid - even you've got gcc installed already.
After some tries - here is complete task list to install VMware tools.
Stuff used in this installation:
- Pure Debian 6.0.6 AMD64 installation (from image debian-6.0.6-amd64-netinst.iso)
 - VMware ESXi 5.0.0 Build 469512 (free license)
 - VMware Tools 8.6.0 Build 425874 (included in ESXi installation)
 
Preparations:
- apt-get update
 - apt-get install linux-headers-`uname -r` make
 
VMware Tools installation:
Begin with inserting installation CD
Then..
- mount /media/cdrom
 - cd /tmp
 - tar -zxf /media/cdrom/VMwareTools-8.6.0-425873.tar.gz
 - cd /tmp/vmware-tools-distrib
 - ./vmware-install.pl
 - Response with defaults by pressing [ENTER] to all question
 
Status of VMware Tools in vSphere Client will update to "Running" just after installation. No reboot required (or any service starting by you manually)!

