Sushi near Staples
The closest would be Katsuya at L.A. Live - literally across the street. While it's more known for it's "hip" atmosphere and fusion-y dishes (spicy tuna on crispy rice, albacore with fried onions, etc.), the quality is more than decent and the prices in accordance with the area/atmosphere. For convenience and proximity, that seems like the best choice. You will have to make reservations, though, because many of the L.A. Live restaurants fill up quickly on Staples event days.
Takami Sushi and Robata Bar has surprised me with their quality.
I'd always assumed sushi "with-a-view" from the top floor of a building had to be crappy. Pair that with the fact they have an attached night-club. A perfect storm of suck right? Actually, no. I've now had numerous meals that that were totally satisfying, sometimes even better than that. Caveat, this is no ZO, Echigo, Sasabune, Mori et al, but I'd go there before I'd go Katsuya...if that says anything. They also have some fun, if overwraught, cocktails.
It is not a short walk, about 5 downtown blocks up Fig to Wilshire, but in no way is it "far." And, there are pretty awesome views.
Takami Sushi and Robata Restaurant
811 Wilshire Boulevard, Los Angeles, CA 90017
Try Sugarfish by Sushi Nozawa. It's on 7th btwn Grand and Hope about a 10 min walk to Staples. It is authentic sushi (sushi nazi style) so if you don't like that then Katsuya and Takami are better bets. Both are equally good and have a nicer scene than Sugarfish and the sushi is good too (same at both places - trendy style sushi). But Sugarfish is the real deal.
11288 Ventura Blvd Ste C, Studio City, CA 91604