I have the CharaChorder One, the Lite, and the 'X'. The Lite is a bit problematic with having to move your hands into awkward configurations to chord. This made me realize that in order to use it, get the CharaChorder One and take the learning plunge. No more moving your hands to other keys as the One switches are 4 directional.
It took about 2 weeks with an hour or so nightly practice, but it was worth it to learn it. Chording has still been another learning process on top of the already mentioned. Overall, a time and cost investment in my health to scale back carpal tunnel and it has helped with the amount that I type. You really have to commit to a niche keyboard, but it saves on your hands and can shortcut typing. I found it a worthwhile move for my purposes, but YMMV.
Listing 4+ because 3 is too few with so many meaningful titles.
Starsiege: Tribes / Tribes 2 - A true successor has yet to exist.
Final Fantasy XI - I miss the magic of Vana'diel.
Furi - Music, story, and gameplay are top notch.
Final Fantasy VII - The original was so much more than I expected.