Usurper,
It depends on what you are after in your betting account. I have quite a few accounts with different online bookmakers.
- Betfair is great, most of the time has the best odds, however I do not use it all that often. I find it difficult to understand with regards to the commision that they charge (as it varies depending on many factors). Also they make it very hard to deposit and withdraw money.

- IASbet is fantastic. Always offer great bonuses to get your money. Great odds.

- Sportingbet.com.au is very good. Great odds. Very simple to use. Very user friendly. Fantastic if you want to bet on other sports also.

- Sportsbet.com.au would be my most used account. This is the simplest and easiest to use. Great service on both the internet and on the phone. Competitive odds, usually comparable with sportingbet (either the same or 5cent to 10cents difference either way). Have now just expanded their "city best" to include the best of all the totes and also the starting price. Offer best flucuation and bookmakers odds 20mins before the race.

My suggestion if you are a serious big punter and are only concerned with the odds go with betfair but also have another online bookmakers account.
If you want something simple and easy to use go with sportsbet.

In saying this I would have to say that most online bookmakers are great and are very competitive.

Good Luck