Do you remember the first game you played on the original Playstation? For me I believe it was Crash Bandicoot. I loved that platformer and thought the console was awesome that it was capable of such awesome graphics for the time.
Metal Slug X was a blast. How many other games do you get to ride an armed camel? This was recently released on Steam. I have been contemplating picking this up again.If memory serves it was Metal Slug (the first in the series, and still one of my favorites) Back then it was pretty cool having the arcade experience in your home, without having to buy tokens!
Metal Slug Anthology is available physically for the PSP, PS2 and Wii. You can probably get it used for a heck of a deal somewhere I'm sure and it comes with 1 through 6. (including X)I have been contemplating picking this up again.