fancyapint.com
is *far* more reliable as being an indicator of a decent pub – in particular look for the 5 and 4-pinters, tho' the 3s will be pretty decent too. (Many of the 2s are ok too, it's more of a relative measure..) It's also got a useful pub map once you've settled on an area.
The (customer-submitted) reviews on beerintheevening, while they *can* be useful (particularly outside London) often have to be taken with a very large pinch of salt. The place we went to after work last week sounded like a dive with useless barstaff, according to a couple of reviews. We ignored 'em, and it actually precent decent. Likewise you'll get larger drinkers complaining about lack of music or lager in a real ale pub. Occasionally you'll get what are obviously partisan postings just to bump up the average.
Yup, there's several nr London Bridge/Borough worth a look (see FAP).
Market Porter has > 10 ales on, only downside is it can get busy (can't think why..) and there's not a lot of seating – but in the week it opens out after about 9pm as the Suits clear off home.
Not far from there is the Royal Oak
http://www.fancyapint.com/pubs/pub1228.php
– excellent for food
The George Inn (owned by Nat. Trust) worth a look (literally) but there's far better to spend time in.
A little walk from Chancery Lane tube – Ye Old Mitre's worth a try if you're nearby.
Several of the Sam Smiths pubs are worth trying – often interesting buildings – eg Citte of Yorke, Princess Louise (both nr Holborn). Bricklayers (Tottenham Crt Road Tube) and Chandos (nr Trafalgar) are decent too.