Noticed the special offer on at the moment, a 30% discount makes this quite cheap. So I guess what I'm saying is, sell me this game. :p

I played the demo way back but that was rather small and probably didn't do the title justice.

Well, if you like good, old-fashioned, resource-gathering, base-building RTS games, this one is sure to please you. The campaigns are nice, if somewhat generic, but skirmish (and multiplayer) games are where EE especially shines. You start off in any era you wish, from the prehistoric ages to the far away future, with only a handful of workers, and build your base to defend it against enemy attacks, while building up your own massive assault force to tear down well-protected enemy positions. Meanwhile, you can advance through the ages to any epoch you want (up to what you've specified before starting the game), getting upgrades for your units along the way.
Besides then more generic RTS units, you also have the prophet, which is a rather nice and dangerous toy if your enemy failed to protect its buildings/armie from his wrath; he can cause an epidemic among enemy units, unleash hurricanes over the seas, or even raise a whole volcano, among other cool things.
The game's epicness manifests itself in at least two areas. One, the scope of the game, which spans 50.000 years; and two, the amount of resources at your disposal (mines have some 300.000 units in them, which won't run out anytime soon), and, consequently, the armies players can build.
All in all, Empire Earth is one of the best "no-fancy" RTS games, where you can literally take your tribe from a bunch of stick-and-stone using barbarians to laser gun-wielding warriors.

Would you recommend the 2nd game in the series over this?

I found it even better than the first game, but it's much more complex (for example, you have to keep an eye on your research points and spend them once you have enough for a research; an other example is that the map is divided into regions, and you can only build a finite number of structures in one, thus you have to secure a number of regions for yourself), so if you want a relatively simpler experience, go with Empire Earth 1.
If you're not put off by the extra features of 2, take that.

Ok, thanks. I think I may hold off on purchasing, have too many games already :p Master of Orion and I-war alone are keeping me busy.

I have to counter and say that I found the second game vaster underwhelming compared to the first. Granted the graphics have advanced and for new players to the game the original might be a little dated in appearance with a rather hollow feeling to the worldset that might deter them.

However I just found the gameplay in the second greatly lacking in "fun". It's hard to put it into words with exact example but the first game just felt far more enjoyable to play, the ai was more responsive - controls were a little tricky (though there is no real change in the new version) - and the eras felt a little more playable.

Just thought I'd update this since I bought EE1. Wish I hadn't missed the BG2 sale price though :(

Have fun with Empire Earth! I hope you'll indeed do find it to your liking.