1 and 2 are ok, Guerilla is like the only proper game about smashing stuff up. If you like knocking down buildings or blowing stuff up, it's the perfect game. I hated armageddon. Took all the best parts of Guerilla and shoved them into a crappy third person shooter.
EDIT: Seems like others liked Armageddon. Just feel the need to point out that this is my opinion before I start a flame war. >I< hated Armageddon. Not saying its an objectively bad game.
"PC has a $0 a year maintenance fee. The only money I put into my PC is buying more games. Have fun with your subscription based gaming." -SirisS-G-P
First was pretty good. Played it randomly a few months back--Looking past it being an "Old" FPS game, it's still mechanically solid.
Never played the second.
Guerrilla was a WTF. Eventually beat it, but damn was that game dull. Amazing destruction physics and incredible weapons...You get 4-20 shots for (If you buy all the upgrades), and then have to either return to base or go to a non-replenishing ammo cache. Spent a good portion of the game using crappy assault rifles because I couldn't be arsed to RTB for ammo after every conflict. And honestly I just found the scale of the map, compared with how much actual STUFF there was to between point A and B...to be very lacking.
Armageddon was a weekending thrill that I absolutely adored. "Structured" (Yes, more linear) gameplay with a HECK of a lot better pacing, and more in line to being a proper sequel to RF 1 and 2. Same great destruction as Guerrilla, plenty of ammo on stock to use your toys, and even the ability to rebuild things you've broken to destroy again. Armageddon was a much welcomed sequel after playing Guerrilla, IMO.