Will this year's E3 be a big one for gamers?
Oh hell yes, without a doubt. As far as I can remember, E3 has never truly disappointed, and there's so many things that could be shown this year....can't wait.
Which system will have the biggest showing? Which one(s) will look pale in comparison?
IMO, I'm thinking PS2 will be the best, for one reason mostly: great RPGs. You may not have noticed this, but I am somewhat fond of RPGs

I just know Square is going to amaze me. Games like Final Fantasy X-2, XI, XII, Kingdom Hearts 2 (hopefully), Unlimited Saga (you never know...), Chrono 3 (!!!!!!!). Not to mention RPGs from some other great developers, Star Ocean 3 (Enix), .Hack (Bandai), and Arc the Lad (Arc Entertainment). But RPGs aren't the only thing I look forward to seeing. Jak and Daxter 2, ICO2, Castlevania, and possibly MGS3.
For Xbox, I have to admit I haven't been keeping track of it a whole lot. But, from what I know, it should have an excellent lineup. Fable is what I'm looking forward too most of all, that game could be what gets me to finally buy an Xbox. I'm also looking forward to seeing B.C., Halo 2, something from Rare, and True Fantasy Online.
GameCube could or could not be great. Nintendo is always so damn secretive when it comes to things like this, so I really don't no what to expect. I hope to see some kind of new Mario game. Mario Kart would be great, as well as a GOOD 3D Donkey Kong game. Resident Evil 4 should be there, along with Final Fantasy: Crystal Chronicles, both look awesome. I'd have to say my least hype is with GCN this year, but only because I really don't know what to expect. I hope Nintendo can wow us.
Which development team will wow us the most?
Hard question. The development team that will be showing the most games that I am interested in, is Square. But that could change if Square decides not to show much or if some other company out does them in terms of games that I would like. It will be interesting to say the least.
Will you fall under the spell of the media?
I should hope not. We'll just have to see what happens.