Adam,
I think you'd be happier in an area of Manama and commute to work, as XTang says its not far and you'll have more social options.
If you move to Riffa, for a night out you'd expect to spend 6-8bd in a taxi (dep on driver) central Manama each way. I believe there aren't that many pubs/bars etc in Riffa, aside from the Royal Golf Club.
The main party area is Juffair, it's close to the US base so more social things have been built up to capitalize on them, but you need a car to go anywhere when it's hot.
I've been living in Adliya for the last 3 years - love my flat, not sure what places XTang saw but there are a range of places for all budgets. We've got about 20 °µÍø½ûÇøs working in our company and the younger ones seem to love what Juffair has to offer. Many of us who don't want to party every night are in Gudaibiya, Adliya. Mahooz and Um Al Hassan - which border Adliya.
Adliya's 'Kebab alley' and the main road gets a lot of traffic at night its true, but that's not all of Adliya! The same can be said of Juffair - which has limited access in and out, making commuting problematic and the traffic on American Alley most times of the day is bad. Amway also has access problems - one road on and off of the island and a lot noise from drag racing up the main roads at the weekend. I had a good friend who was there for 2 years.
I like the Adliya area because I can actually walk around, there are places to go and I don't need a car. There's a pedestrian block with art displays and TREES, so it feels a lot more European. Many restaurants sell alcohol and there's also JJ's Irish Pub, and a couple of small night clubs attached to the Meat Company and Brazils restaurants. There's also the British Club - which has cheap food and drink and sports facilities.
Also look at other areas south of Adliya; Mahooz & Um Al Hassan - easy access to the southern highway and less traffic. Friends regularly walk from there into Adliya.
Some workers with families are out Saar way, it's nice but more rural and a car is needed to go anyway as it is more spread out. But it has good access to the highways. I go horse riding over there and it's about 10-20minutes from Juffair on a good traffic day. As another member says there are options with the Dilmun club etc.
A car (or driver) is a necessity, which is crazy seeing how small Bahrain is. I bought my first car in 15 years here and it's the smallest place I've lived in! Driving is initially a bit strange compared to the UK, but you adjust and it's not as bad as Cairo or Amman in Jordan.
I hope some of that was helpful, is your company putting you up at first? We had 2 weeks in a hotel, which was great to get the feel of places and check out places to live.
Good luck
Michelle