Been eating a good amount of sushi lately and have really noticed the differences between a few places.

Koto: I am pretty confident this place is the best when it comes to nigiri/sashimi. The quality is great and the portions are very big. They also allow you to just order 1 piece instead of the normal 2 like most places. I like this because it allows you to get many different kinds of fish. Last two times i have been they have been out of fatty tuna but they have had sweet prawns which are awesome. Eating the fried head is really tasty if you can get over some crunch and the idea that you are eating the head of a shrimp.
If you are a fan of rolls, this is also the place for you. During weekdays they have a list of specialty rolls which you can order from and they all are half the size/price. Once again this is great for allowing you to get multiple rolls to try. Im not the biggest fan of rolls but all the ones i have tried were very well put together with a wide range of tastes.
Koto is probably the best place in BR as a whole in terms of quality,freshness,variety,and atmosphere.

Ichiban: I put Ichiban right alongside of Koto as 1a and 1b in Baton Rouge's sushi scene. Their nigiri/sashimi is top notch and they always have fatty tuna which is alittle pricey but it is to die for. Its $9-10 for two pieces but it blows away regular tuna by a mile. If you like dumplings, they have some of the best I have had in BR (i know i made a thread not long ago about dumplings and where to get them but I have been going dumpling eating crazy and have had plenty since than). They generally run appetizer specials and the oyster specials are always great along with the mussels. Some of the best mussels in BR.
Once again, I dont eat rolls very often but the rolls at Ichiban are always good and they have a very large sushi roll menu to go along with it.
My only complaint about the place is that sometimes its very dark in the back dining room and there isnt much room between the tables. I would rather not hear the conversation on the table next to me just as well as the convo on my table. Im really being nitpicky here but it is noticeable.

Waka House: I went here recently after a long break and once again there was no one in the place. It was the third time that I walked in and no one was there. I kinda marked this up to BR being oversaturated with sushi joints. I also notice that Waka House seems to take on more of a traditional Japanese route with some of their dishes. This might cut down on some of their business with it being jammed into a college kid area.
Their lunch boxes are very good and have a good bit of variety between them. Some have dumplings and some have grilled shrimp/chicken skewers. Their dumplings are great but the sauce that goes with it is not the best to say the least. I dont know exactly how they prepare the dumplings but they seem to be steamed primarily and then finished off on the grill for a quick sear. The salad also came with Italian dressing which struck me as a little odd. The rice dish that comes with the box is very spicy and reminds me of chinese kung pao.
On to their nigiri.......WAY too much rice. I had to take off half the rice when eating their nigiri. I dont get the reasoning for that much rice but it is definitely noticeable.

Sushi Yama: This place is now 3rd best in BR in my opinion. Keep in mind that I am not big into rolls and thats what I have heard they are best at. I also for some reason always find my place here for lunch. They give you a cucumber salad to start every meal which is always a good way to start sushi eating.
Their nigiri comes in very small portions but is of great quality and freshness. It is right up there with Koto but is just so small that I dont want to go back when Koto is right down the road. I want to chalk this up to it always being lunch and they just dumb down the portions because of that. If someone can validate this, please do.
Their lunch box is pretty much your normal box but comes with tempura shrimp instead of dumplings. The roll is either a california roll or a combination of spicy tuna roll. It all depends on what chef is making the roll. Kinda splitting hairs here but I asked what roll I was gonna get last time and the girl couldnt tell me.
The meal always ends with slices of pineapple which is a cool way to end a sushi meal.

Koi: Im gonna add this place because I have been there a few times for lunch recently but its not on the same level as the other places. I gotta start out and ask if this place owns an air conditioner. It is always hot and stuffy when you walk in and the last time I opened the front door I literally had to move a 8 foot tall plant that was in front of the door. We kinda laughed at how absurd it was.
Their lunch box is a very good bang for your buck deal. Its less than $10 with a drink and does the trick if youre hungry. They put so much dressing on the salad which is annoying. The salad is almost like a soup. The nigiri in the box lunch is pretty good and the portions are large for the price. The salmon teriyaki tastes good but the salmon is ultra thin and has been a little on the dry side both times.
Once again its a great deal for your money and is a great place to eat in between classes if youre a student.

I would add more right now but I type slow as hell and I cant look at the screen much more right now