To my ears, nothing sounds as good as an amp miked up. That being said, I've never used Garageband, so I have no idea how good - or not so good - the amp sims are, I'll have to take your word for it that they aren't great.

I've used Amplitube, Vandal, and some Waves Virtual stomp boxes... sometimes they work for what I'm doing, but most of the time I use them only to get ideas down, or if I'm tracking late at night, but mostly I end up going back and re-tracking them with my Fender Hot Rod DeVille. For your situation, you might want to give Amplitube a try.

Amplitube is IK Multimedia/T-Racks, so I'm pretty sure that, like the rest of their processors, you can download fully functioning trials for 14 days (it may be 10, I don't remember).

You'll need to download their Custom Shop Application, from which point you can try all their processors, including Amplitube.

Go to ikmultimedia.com and register as a new user, then download and install the Custom Shop application, after that, select Amplitube, and pick and choose which amp sims you want to try.

end note: as a trial user, you'll need to keep the CS app open in the background while you are using the various amplitube plugs in your DAW.

Rufio90210, post: 429025, member: 44172 wrote: I just find my guitar sounds flat and lifeless in garageband, Ive played around with settings and although theres lots of great sounds the LIFE and FULLNESS is just not there

You say you bought a DI, doesn't your interface have instrument input ??

Guitar tone obviously starts with the guitar itself but the rest of the signal chain is also important.
I was exactly where you are a few years ago until I bought my first high-end preamp. Well it was the cheapest of what I'd consider High-end, the Focusrite ISA. They are good mic preamps but also have an DI instrument input. At first try, I heard a world of difference from my audio interface.
I also use Samplitube from time to time and get acceptable results but defenitly prefer a real amp.

One other avenue you could explore is using an hardware amp simulator like a line 6 Pod HD or others.
I say bring your guitar and headphones to a store and try a few ;)

pcrecord, post: 429041, member: 46460 wrote: You say you bought a DI, doesn't your interface have instrument input ??

Yo, I have bought a DUET 2 interface it hasn't arrived in the post yet. But I was intending to DI BOX my guitar and then run it into the XLR input of the DUET 2 so that I can use its preamps. As my understanding is that the instrument input does not use the preamps.

Try it both ways. You may find you prefer one to the other, or they may sound very similar.

I agree with Boswell.
I found that depending on the Di Box you have, the instrument input may sound better.
Congrat on the duet purchase, it's a nice interface !

When you get it, it would be interesting it you'd post some samples here; with or without the di box ;)