1. Alter Ego: My favorite class. Best set of passives, interesting toolkits and very flexible, even if they end up doing less damage than using the proper counterclass. I have a lot of fun using them, and sometimes even fight against Knight classes with them if I can get away with it.
2. Lancer: From the 7 basic classes, my favorite. Most of the Servants in it are really good and you have a lot of options to choose here, both AoE and ST, with some hybrid damage dealers and support too. The only bad thing is that they usually only have MR, which is an okay passive but they lack something that boosts their damage unless the Servant has an additional passive
3. Ruler: Really fun class to use. Their tankiness is really appreciated and doing class neutral damage is not an issue nowadays as you can use supports to make up for it. I find the current content makes them shine even more too, specially after the release of Astraea which is a really good ST Ruler that is available at all times.
4. Archer: I do like their crit focus part, which ends up making for some really crazy damage sometimes which makes up for their lower ATK modifier (like Superhuman Orion), and there's a lot of good options for both AoE and ST in it, but I still prefer Lancers as they're a bit more flexible sometimes in what I can put with them, and the Archer star absorb can sometimes get in the way in case I need a support to crit to get more NP.
5. Avenger: A fun class, they are what IMO Berserkers should have been if they wanted to create a glass cannon class. They have the second best set of passives, specially that constant NP regen. A bit of a pity that they have crit damage but bad star absorb, it's a weakness that you have to make up for if the Avenger doesn't have a way to fix it temporally, but their high attack and offensive focus kit makes up for this a bit.
6. Rider: I use this class less and less since I find myself using Alter Egos against Casters. That said I can't deny a lot of them have great tookits and there's both good ST and AoE options. It's just a pity that they lack something that makes me really like them as much as Lancers or Archers.
7. Saber: Very average class. Most of them don't benefit from Riding so usually they only count for one passive. They also lack good AoE options, the worst of the 7 basic classes in that part. That said there are some really good Servants in it and Lanling was a very appreciated Saber to get after a long time with only damage dealers, but overall I think this class lacks something to make it as interesting as the other classes.
8. Casters: Don't get me wrong, this is the most broken class if you look at the supports. But this class seriously needs more options for damage, specially ST. Caster Shuten was a much needed Servant in this class, but we still need a bit more to cover the ST part. Also most of them are Arts focus, very few of them benefit from Buster, and none are Quick focus which really kills potential teams you would want to try with this class.
9. Berserker: I don't like this class. It may have Altjuna, Cu Alter and Heracles, but the class itself is something I don't like. They pretty much need heavy babysitting if you want them to live long due to their weakness to all classes, which encourages quick clears which is not something that most people can't do or want to do. IMO Avengers do a better job at being glass cannons, sure they do less damage and they still die faster than other classes but for CQs they're much less cumbersome to use than Berserkers. The current content has made me like the Berserker class even less, and I mainly use the three I mentioned before because they are incredibly broken in their class.
10. Assassin: The class that definitely needs some revamp. It has the least useful passive in the game since it only benefits Servants with high hit count, and high hit count usually ends up hurting their NP gain (except in few Servants) which is not good tradeoff, specially when there's many other ways to generate stars and even if you get more stars than normal when attacking you're not guaranteed to crit or have a hand that benefits from it. They also got hit with a lower ATK modifier for some unknown reason, they really should have made it 1.0 at least, the lower damage is noticeable, specially since Rider Servants tend to be tough in challenging content. Sure, there are some really good Servants in that class like Kama, but when a Servant is released in that class, I find myself having less excitement over said Servant than with other classes.
And as for the rest of the classes which I don't rate because there's not enough of them to make a good point:
- Shielder: Give me back Normal Mashu, I want to do Mashu + Ryuutan combos again...
- Mooncancer: Not enough Servants to say anything. But tbh, only 4* BB can be considered to be good and that is only for dealing with Avengers or stall teams. 5* BB and Jinako don't really offer anything special to make the class shine.
- Foreigner: Still not enough Servants, but if I have to say something, their anti-Berserker gimmick means nothing to me, specially when in challenging content the Berserker bosses easily ignore the class advantage (hi there Altjuna). From all of them MHXX is honestly the most fun as she doesn't have any glaring flaws compared to the others, but it's still a class that needs to provide something more than the anti-Berserker stuff. The release of Yang Guifei made me believe that even more.