Go for the ROTF figures. If you need financial motivation, think of it this way. In 20 years the ROTF figures will increase in value. On the other hand, in 20 years the XBOX360 will probably cost less than a Big Mac extra value meal.
I say Xbox 360 because ultimately you will use it more than toys, and you can slowly pick up ROTF toys one by one .
But you can't just remove PC from that equation. If you have a good PC then the 360 has pretty much nothing going for it over the other platforms.
ROTF figs as they can't get the red ring of doom/death ( not sure if they fully have that fixed yet )
I play with my TFs way more than my 360. If you are a MISB kind of guy, buy the toys, wait 5 years and sell them, then have the money to buy whatever system is best then.
I'd say get the console. Sooner or later ROTF stuff will be in the sales and you can get em cheap then
Wasn't sure if the poll was for the system or just the 360 game? Anyway, I'd say the figures first, game (if that's what you meant) second. Only reason is that the figures, while they may go on sale at some point, may become increasingly harder to find. While the game will just continue to drop in price as time goes by. So my logic tells me, grab the figures while you can, the game will always be around!
Ignoring my general dislike for most Bay figures, I'd say get those first. Nothing worse than skipping buying figures only to not be able to find them at a later time, or finding them but the prices have gone up due to rarity/popularity of certain characters. I'm sure you can find an Xbox at any time, and usually games consoles go down in price as time goes on. Same goes for the games for the console. And once you get bored with the TF figures you can flog them for games and stuff.