Which 3G Phone is the Best?

So recently I've been really getting into Twitter and Facebook - to the point where it's actually counterproductive - but what the heck, I love it.

Basically, I have a clunky old Nokia N73 that is way past it's upgrade deadline and I want you guys to help me pick a replacement.

Clearly, I'll be posting a lot of tweets - updating my Facebook and generally interacting with you all via social media on the new phone.

So which is best?

I won't really be using the phone that much for actually talking with people... lol? I'm more of an email/social media person when it comes to that. So it's basically going to be used for surfing, helping me manage my business, staying in touch with loved ones and an emergency communication tool when required.

Please comment with your opinions on the following phones, or if you know of a better phone please also let me know what it is and why you think it deserves my attention.

Here's the current running for the new replacement:

Iphone-3g

Palm-pre

Blackberry-bold

T-mobile-g1

Htc-touch_diamond