You would still want to consider living in a compound because there are restrictions on where single guys can live. Neighbourhoods are segragated into family and bachelor accommodation. Bachelor accommodation is not suitable for westernised professionals, believe me! The areas they designate for this are total crap and half of em dont even have paved roads!
Compound is the only way to go. I stayed at Seder village
excellent quality western style compound & corporate accommodation in Riyadh, Saudi Arabia : Seder Village: expat community and loved it. Good mix of nationalities, a bar that opens at weekend plus a few midweek nights and they show all the big games on their projector screen TV. They brew a half decent beer and it's a welcome treat after a hard day. They have a restaurant, gym, pool, decent internet and is not far from down town if you're tempted. I paid 1,000eur0/month for a one bed place plus utilities which were negligable.
Getting into these places can be hard however as the waiting lists are getting longer. After the terrorist attacks in 2002/2003 etc the compounds were like ghost towns as everyone fled and units were rented out for whatever they could get. The times have changed now and unemployed victims of the global recession are starting to head back that way out of desperation so there is no shortage of people who need a place to stay.
Furnished apartments, or 'aparthotels' as they sometimes call them are fine for short stays but they will be thronged with reclusive locals at the weekends who arrive from the boonies with their 2 wives, 12 kids and Indo maids. They'll all go out to shop in RUH's multitude of malls and then keep you up half the night while they run amok inside the apartment.
Apart from Seder there are Al-Hamra (one of the best in RUH) and Arabian Homes. Both are very central to down town and the airport highway however they are very very expensive to rent. FAL compound is another option however it is 2nd rate, quite dated looking and not so many westerners live there anymore.
If you need any more info then feel free to PM me..
D.O.G