Wow, this topic is going a bit crazy. I like it. There are a lot of opinions and advice and hype for different games in the 'genre'. I also like that for the most part people are staying civil! So often these topics become an argument and people get defensive for their hunting game of choice. Happy to see that hasn't happened much as there is a lot of fun to be had in these games, and we are all obviously huge fans of them.
I think this bit of advice from Shengar is spot on:
if you want to enjoy all the game available: treat the game as separate entities with their own gameplay uniqueness that shouldn't cater to your specific gameplay preference.
While there are countless similarities between titles they really are their own lovely gems. I started with Monster Hunter so that will always be my true love in the genre. Thousands of hours in the series. My favorite franchise out there, so know that before you read MY opinions on some others. Also, it should be noted that I approach all of these games with soloing being how I will spend the majority, if not all, of my time. This works great for some games, and not as well for others.
Folks play the game to challenge themselves and have a good time with friends more than playing by yourself and enjoying a story.
That is exactly what I love about Monster Hunter. I never had the opportunity to use XLink Kai back in Freedom nor did I have anyone to play with locally, so I learned the game myself. It. Was. HARD. I loved it. There is nothing as satisfying as taking on those High Rank, and later G-Rank, missions alone and eeking out a win. You get better, you learn, you get even better, and you feel like you are truly mastering something. I imagine that is how perfecting a fighting game feels.
Anyway, that fondness made me seek out other games, and while some have been enjoyable, hardly any have clicked that way. PSO I want to love, I do, but it hasn't sucked me in yet. I think it is due to the archaic feel that someone mentioned. It feels... too different. GEB, I really liked, but I was playing it in Japanese and the bullet creation was just... brutal. I have since grabbed it and am playing it again on my Vita. I quite like it. Again, it is different.
Soul Sacrifice, I just do not like this game. I don't love the story. I don't love the material management or the fighting style, or the enemies. The maps feel very small (a complaint I have with most games in this genre though... other than MH and TOUK) and more like arenas.
Toukiden I enjoyed, but like Parakeet says, it feels too easy. Lock on and smash bits with your weapon/combo of choice, knowing when to back away. Not a lot of strategy changing from boss to boss. The game is pretty, the weapons are fun, but the bosses all feel like the same fight, same approach, different enemy skin.
Freedom Wars feels the most different, and I am loving it so far. It is a refreshing change for me. The locale and atmostphere is odd, the restrictions are a very refreshing way to give you something to grind for. Can't afford to buy the right to run for 10 seconds at a time? Better go grind the points! The fights so far are challenging, but not brutal. That could be because I am only Code 5... almost have my Code 6 test open. We'll see. I have played a few times online to see how it is, and it is smooth.
Ragnarok Ace... ugh. I sunk a huge amount of time into iRO many many years ago, so I was a fan of the 'lore', the world, the jobs, etc. Then they announce a hunting title in that world!? I was so excited. Again though, so boring. So lifeless. As a solo player, it was often times quite crushing as well.
Finally, I attempted to play Lord of Arcana a few years ago too. I will try anything in this genre if I am able too. I truly want to love them all. Lord of Arcana also fell very short, was not very challenging and the lock on took a ton out of enjoyment out of the game. I did like the limited story that I saw though.
All I can add, read up on how these games play. For being related and in the same family of games, they are as different as your own family likely is. We can all offer out opinions too, but as you can see everyone feels very differently about each of these titles. It is really hard to tell someone if they will like one of them. They all have a lot to learn. They all can be very brutal. They can also all offer a great deal of fun, challenge, rewarding gameplay, and if you have a group to play with... a really great cooperative experience.