Solid, affordable, basic monitoring that could use work

If budget is a concern and you are mainly looking for basic up/down functionality, then I would definitely give SolarWinds a look. In pretty much any other scenario the unintuitive settings UI and all over the place features and functionality make it difficult to use and configure beyond those basic features. In trying to make it simple and easy it has been dumbed down too much and hides the useful features in out of the way places that don't make it simple or easy to find and configure what you are looking for. It still blows my mind that I can't duplicate an object to make creating new similar objects easier instead of having to populate 20+ fields of a new object by hand each time.