As others have already suggested, disregard the LX and stick with the Zetec & Ghia models. Personally though I would go for the Zetec as it's aimed to be a bit sporty. Even though I've never owned a Mondeo but I have owned a few Focus's, this is the way that I see it and this is how it is for them so it may still differ for the Mondeo:
LX - sometimes you get air con or a heated screen or even both, standard comfortable suspension setup, front electric windows, steel wheels or sometimes the entry level based alloys, usually you get remote central locking as standard, no fog lights, standard interior.
Zetec - ABS, air con, remote central locking, more appealing alloys & interior, front electric windows, front fog lights all as standard, heated front screen is usually standard too, upgraded suspension that adds a sport feel (usually just stiffer springs) as standard. I believe Traction Control was an optional extra too.
Ghia - ABS, air con, remote central locking, the premium-ish Ghia interior & exterior with the fake wood trim (looks awful though!), front fog lights, heated front screen, traction control, Ghia alloys, Ghia comfort suspension, electric windows all around usually - all as standard. I'm led to believe that the 6 CD player, ESP & cruise control was an optional extra as well.
If I have missed anything out or if I am incorrect in places then I do apologize, but that is just a rough guideline

In my opinion though, I would just stick to the Zetec as it's the best of both worlds.
Liam