I've used Ignite and Spotlight, and also a third one notmentioned in your list; Quest Foglight.
Ignite and Spotlight are really doing different things.
Ignite is mainly for monitoring wait statistics, and it does so very well in a very easy,intuitive and fast web based GUI. It's easy to install and does not require anything to be installed on the monitored server instances.
Spotlight is more for monitoring of backups, jobs, disk, cpu, memory. Also easy to install and does not require anything installed on the monitored servers.
We ended up with both Spotlight and Ignite.
Regarding Foglight: My personal recommendation: Don't go there. The web GUI is sluggish, you need a master degree to install. Monitoring stops at least once a month. Quest has been trying to fix this for us for over a year, but no progress has been made.