Well I tried that Monster Hunter shit... I managed to defeat the first one pretty easily. It takes a while, but I blew the fuck out of it with rockets. Apparently that's not what you're supposed to do, though. You're supposed to blast pieces of it off (according to the reprobates at GameFAQs, anyway) so you can use them to make stuff. I'll give it another go later.
The second monster, though... Tigrex. That fucker is impossible. I seriously don't know if I can do it alone. My weapons aren't fully developed (far from it), but even with maxed out gear I don't see what the fuck I can do. It's so fast that it can be all but impossible to dodge, and sometimes it charges you repeatedly as you lie on the ground like a chump. Each hit takes you within a cunt hair's breadth of dying, so your rations are gone in no time. I managed to get it halfway dead and that was it, and I was using rockets. Clearly this was designed for co-op — frustrating stuff, what can I say.
Also, I know what 'Duf was talking about back in the day. I don't want to spoil anything for anyone, but after you beat the game proper, you can go on a 'date' with Paz. I won't say how it ends, but given the fact she's sixteen and Big Boss is damn near forty, it's creepy. What the fuck were they thinking.