The following sportsbooks have been found to be able to get ACH/Instant Check Deposits/Tranfers to work smoothly:
betED - Generous sign up bonus promotion as well. See their site for details.
Sportbet - 50% initial bonus when using echecks. 20% when you use a bankwire to deposit. Reduced juice -105 on Tuesdays and free 1/2 point Thursday's. One of oldest books on the web.
*Note: Funds will show up approx 6 days after you deposit using echeck option. This is to prevent against FRAUD which they were having a problem with.
BetLasPalmas - Offers a 20% sign up bonus. Depositing is easy here with echecks. Call their customer service for exact directions on how to complete the transfer.
5Dimes - Max deposit $300. Funds are instantly deposited into your wagering account. Takes 14 days to clear. Can't make NEW transactions until previous transaction has cleared. ***Note: 1st transaction must be made using moneygram or western union. THEN your eligible for echecks. Great sportsbook!