Definetely a Tube pre-amp is going to help. Also have a look at the Line6 POD and the new Native Instruments Guitar Rig. I think the thing with Amplitube is, if you want something to sound a certain way you have to be willing to modify presets (you might already do this). The presets should only be used as a guide because every guitar is different and what suits your guitar might sound crap for mine. Amplitube is quite a powerful and versatile tool when you have a dig and find out what it's capable of.

I'm still waiting on my NI Guitar Rig to arrive, but the demo is getting a good work out and I'm now conviced that it's certainly better than Amplitube. NI Guitar Rig demo is available @ Native Instruments website for download. It's a new toy that hasn't yet bored me, as I'm constantly still fiddling with it and this is strange for me as I don't normally get excited about software.

Good Luck finding 'that TONE'

I've been playing/recording guitar a lot longer than I've been recording anything (or anyone) else - and I've tried EVERYTHING at one time or another.

1. Amps do sound better 99% of the time. There are times that direct works, but most of the time an actual amp is preferable. (this is my opinion, but the vast majority of recordings are done this way)

2. If you can't crank an amp due to where you live, etc - build a "dummy chamber". I did this when I lived in an apartment years ago. (it's basically a 1x12 speaker cab inside a box with a mic) It's not the same as an amp in a room - but it's a lot closer than direct. I have measurements for mine if you're interested.

3. POD, etc - not bad.. and at some things, exceptional.

4. Stompboxes into a speaker sim (easily built - check out diystompboxes.com for info)

"-)

My latest project features a vast mix of different guitars, different amps, POD & Sansamp modules and with the exception of ONE track (out of say 50), the mic'd amp sounds the best.
I started with a AKG C3000B which I later replaced with a 57 and the tracks with the 57 sound best..

Although I used many amps, this combo sounded the best..

Marshall Plexi plugged into the speakers of a Vox AC30 (Blue Celestians) , a 57 close-mic'd on the speaker edge run into a ART Tube MP then into Mackie Board, slightly EQ'd and a touch of DBX compression then sent to Echo Mona interface...

Nothing beats a real amplifier, but you can get pretty close with POD or the software effects. I've been playing around with Guitar Rig, and jeez, I must say, I'm impressed! It sounds VERY convincing indeed, and if you crank up those monitors until the ground starts shaking, you might just notice a slight difference...

The worst thing about the amp simulation plugins is they drain the computer extremely fast, so you can't have a whole lot of them hooked up. But apart from that, I'm really amazed what software can do these days.