I recommend "HERO'S" in Akihabara.
You can eat one pond steak or handmade hamburg .
It is not so expensive but delicios.
Casual steak restaurant may be Ikinari Steak.
I haven't been here, but apparently the restaurant is getting popular. I see people lining up all the time.
For more promised quality, teppanyaki restaurants would be recommended. Such as Ukai or Sagagyu Kira.
Gyukatsu, deep fried beef (beef version of tonkatsu) is getting popular. Ichinisan in Akihabara is popular.