Game Engines: Any Recommendation on What a Beginner might try?

[Anthropoid]

I want to try to put some of my ideas about turn-based strategy game into practice. I've been looking around at freeware game development engines and I'm honestly stunned by how many different choices there are. I'm sure that every engine has its pros and cons, but I'm not really even sure which ones are good possibilities for my purposes.

Out of that lists the ones that seem like they might fit with my needs are:
Angel2D
ClanLib (SDK seems useful)
Polycode (wow that sounds pretty amazing really)

2D Turn-based strategy is definitely what I have in mind.

Two other possibilities that I've downloaded are C-Evo and TripleA.

My goal at this point is to just 'get my feet wet' and hopefully come up with something that is functional, even if it is not suitable to expand on. Mainly a learning experience that might lead to something that players could actually use.

The games that inspire me the most are:
Civ 3
Crown of Glory / Forge of Freedom series
Distant Worlds
East India Company

Any suggestions on which engine(s) I might look a bit more into?

[pakfront]

Unity is quite capable and well documented. It is a bit of a jackknife though, so expected to get a few minor cuts.