Here are some of the VMware VM monitoring tools .
- Solarwinds Free VM monitor
- Veeam Monitor for VMware Infrastructure
- Zenoss
- NimBUS Vmware monitoring
- VizionCore vFoglight
- PacketTrap
- Akorri BalancePoint
- Vkernel
- Hyperic
- Hyper9
If there are some more left in this list , please leave a comment.