I'm always alternating between games. But lately, I'll be playing a game like, say, Splinter Cell and I would think "You know what I really need right now? A tank, yes I could really use a tank or perhaps a gunship right now".
So I'll switch on the PC, load up Operation Flashpoint and either continue my Resistance campaign, create my own custom battle with the worlds greatest Mission Editor or download one of the millions of third party missions & campaigns.
This game, IMO, has more playability, lastability and variety than MoHAA(FL), GTA3, Halo, Counter Strike, Splinter Cell, Ghost Recon and Delta Force(s) together.
In case you haven't worked it out, I like this game.