The G-Major has consistently been one of the most popular processors in guitar rigs because it a) sounds great for chorus/delay/reverb effects, b) is very easy to program, and c) is dirt cheap for the quality of the sound.
There are others who swear by their Rocktron gear, though.
If you want to read a review of the G-Major, G-Force, and some other gear, start here:
http://www.musicplayers.com/reviews/guitars/2007/0307_TCElectronic_G.php
Don't forget that if you make this switch, you'll also need to invest in a MIDI foot controller. If you're new to that, too, here's a good tutorial and buyer's guide to start:
http://www.musicplayers.com/tutorials/guitars/2006/0306_MIDIFootControllers.php
If you're a BOSS Pedal lover, you might want to consider the BOSS GT-Pro:
http://www.musicplayers.com/reviews/guitar_bass/2006/0306_BOSSGTpro.php
Personally, I've used a G-Major in numerous Marshall and Mesa/Boogie rigs and been happy with everything other than filter and wah effects, because those sound best in front of your amp, but the G-Major sounds best in your effects loop, where chorus/delay/reverb sound fantastic.
Scott