The best for the least amount of money are the new Life Like diesels. I have mostly Atlas with Kato motors and they are excellent.
High speed is a little unprototypical, but they are quiet, pull well and look great.
In summary you should be OK if you go with new Life Like, Atlas, Con Cor or Kato. Depends on your budget. I can't speak for Steam Locos. Life Like diesels. Life Like, Atlas, Con Cor or Kato.