Hi. Does anybody use a pod or other Hardware guitar processor before you get to the computer? If not what would you suggest as a guitar plug-in with lots and lots of cool presets?
Hopefully this forum is okay for that question?
WSS

I have used just about every hardware unit out there. Boss units, Yamaha, Digitech, etc.. The Line 6 POD series is probably the most affordable for the quality out there. If you can afford it, the next step up would be a Kemper or Axe-FX but they are pricey. For the last several years I have used nothing but software plugins and have loved every minute of it. Amplitube 4 is getting used on just about everything I do now. I much prefer using the software because you can record the track and if you want to change the amp later you can without the hassle of reamping or recutting the track because the sound wasn't right.
Short answer is hardware units: Line 6 Helix or POD HD500X. (You can pick up older POD HD500s for a very reasonable price if you can find one!) Kemper, Axe-FX.
Software: Amplitube 4, BIAS Amp, S-Gear, TH3, Guitar Rig.
I personally prefer Amplitube 4 but you really need to add the Fender, Fender 2 collections. They really are the crown jewels of Amplitube!! I hear the Mesa Boogie collection is astounding. I have never been much of a Boogie guy but I have heard so much good about that collection I might have to invest in it.

Thanks for the info. I guess the convenience of switching sounds in a software plug makes a lot of sense. Do any of the plugs come with a plethora of presets and are any suitable for an acoustic guutar input as well?
WSS

Scuffham S-Gear is also very popular and affordable. To me, of all the ampsims I own (Amplitube, TH2/3, Waves GTR3 and Guitar Rig) S-Gear sound the most like playing an actual amp. Disclaimer: I'm a keyboards guy and only dabble in guitar playing.

If you pick a sim it can also help to get one that allows you to use custom/3rd party cabinet impulse responses. There's a few professional idiots out there who have sampled just about every cabinet out there with different mics at different distances and angles. It can make a big difference in sound. E.g. S-Gear uses cabinet IRs from Redwirez, and Redwirez sells a "big box" with a huge amount of IRs separately that you can also use in S-Gear.

I try and get the guitar sound before it goes into my DAW. There's something organic about using an good guitar pre amp and speaker in the signal chain that is the only thing I find satisfactory. I bought a Blackstar amp which is a lot of fun and is capable of anything, but it just doesn't sing the blues or twang enough. So it does depend on the music style as far as that goes. I stick with my stomp boxes and a Fender Tube Amp because that is what gives the bite and tone for my style of music. 

Sanderxpander
If you pick a sim it can also help to get one that allows you to use custom/3rd party cabinet impulse responses. 

FWIW TH3 Cakewalk Edition can load IRs, and comes with a bunch of them.
 
I've worked with amp sims for a looooooooong time and I feel what's most important isn't the amp sim itself, but what you put before and after it. For example, I use a multiband compressor to "de-ess" the guitar's highs when running distortion...tune the output with notch filters...restrict the range of frequencies going in...that sort of thing.
 
I'm creating a new set of CA-X amp FX Chains based around TH3 Cakewalk Edition. The original set was kind of a disaster because there had to be two different versions, one for SONAR Artist/Professional and one for Platinum, and whether they worked or not depended on how TH2 was installed. So some people thought they sounded fantastic while others thought they sounded horrible...both were right 
 
The new chains will be unlocked so you can reverse-engineer them. IIRC one of them has 24 filter stages at the output and if you remove any one, it doesn't sound as good (although I also use them to create tone stacks, not just for tuning purposes). For example here are the modules used in a new high gain CA-X amp head called Fat Gain.
 

• Sonitus Multiband
• Sonitus Gate
• Sonitus Equalizer
• Overloud TH3
• Sonitus Multiband
• Cakewalk Multivoice Chorus/Flanger
• Sonitus Equalizer
• Sonitus Equalizer
• Sonitus Equalizer
• Sonitus Equalizer
• Sonitus Reverb
• Sonitus Equalizer

Sanderxpander
Scuffham S-Gear is also very popular and affordable. To me, of all the ampsims I own (Amplitube, TH2/3, Waves GTR3 and Guitar Rig) S-Gear sound the most like playing an actual amp.

I own a couple of amp sims, but after reading your post I decided to take look at Scuffham S-Gear and I'm impressed. Good call.

S-Gear is very good indeed. Just make sure you don't overload the input, but that's true of all amp sims.

I'm a big fan of Amplitube and Guitar Rig sims (but to be honest, i haven't tried many others).
 
Amplitube excels at simulating specific amps.  If you want that '65 Fender Twin or Marshall JCM800, that's what you get. It's very straightforward and simple.  They're licensed to Fender, Orange, Ampeg, and others, so they have to be great recreations.
 
Guitar Rig doesn't seem to mimic specific amplifiers as proficiently, but I use GR when I want a more complicated setup.  You can drop in their "marshall sim", split the signal and send one line through a noise gate, which then routes to a different amp, which then splits again and has the upper frequencies panned Left and the lower frequencies panned right, with separate Delays on each.*
 
I also have a Boss GR-10 around somewhere, but since I have these sims I never really use it.  I've also got a Line6 Spider amp which I could use to hard-code the sound, but the flexibility of the software wins every time.
 
* I've never actually tried this, I just made it up as an example.
 
 
 

Slugbaby
Guitar Rig doesn't seem to mimic specific amplifiers as proficiently, but I use GR when I want a more complicated setup.  You can drop in their "marshall sim", split the signal and send one line through a noise gate, which then routes to a different amp, which then splits again and has the upper frequencies panned Left and the lower frequencies panned right, with separate Delays on each.*
 
* I've never actually tried this, I just made it up as an example.

 
I have, and it works fine. The Crossover and Splitter modules are the key to multiband processing in Guitar Rig.