i have a Roland Micro Cube for an amp and i was thinking of upgrading it. i was looking around and i found guitar rig. i thought i was ingenious but it cost quite a lot of money. then i thought with that kind of money, should a get a more decent amp or should i get guitar rig?
what a dilemma, any help?
Depends on, if you're often sitting in front of the computer while playing... And/or if you want to make a lot of noise :P

Edit: And for guitar rig you have to have something where you can plug your guitar to the computer - I guess.
Get an amp, ive used my friends micro cube and i think its the perfect practise amp, if you are a hobby guitarist micro cube is the best, unless you go for the professional range of amps which costs a good amount.

I started off with Guitar Rig 3, thinking amps are a waste of space in my room and regret it. There is latency when you use it through the PC, even in mid range sound cards. Even in a Creative audigy II platinum i got around 20ms delay which is quite a bit when you play tapping solos and fast riffs. So get ready to spend 400$+ on a pro audio card. Not to mention you will waste 50% of the time setting it up !! On the good side, you can get any sound/tone you want.
personally i up-ed to my fender super champ xd amp and i realized what i as missing
its a small tube amp with a SWEET sound
highly recommdn
Taylor 314CE
Modulus G2T and G3CT
3 Warmoth Guitars
2 Fender MIA Strats--SRV & JM
Alvarez w/ Modulus Neck and EMG DG-20s
Marshall JCM 2000 DSL 50 w/ 1960a cab
Breedlove AC250/SM12
Gold Tone Weissenborn
Adrenalinn III & FCB1010
ALOT of pedals
For recording Guitar Rig is pretty hard to beat. You get multiple amps, effects and the USB & recording software with it for ~$99 CAD. If you want to record backing tracks or songs it can be very useful.
An amp is also good to have too though but you won't get much of an amp for the money GR4 sells for.
Moving on.....