The Golden Union Fish Bar has THE best fish and chips I've ever had in London, and I ate fish and chips very regularly while living there. The portions are huge, the batter is perfectly crispy, the tartar sauce is amazing, and the chips are delicious. It's tucked away on a side street off of Oxford St. 

You should definitely try the The Rock & Sole Plaice

47 Endell St

Covent Garden, London WC2H 9AJ

The Golden Hind in Marylebone is my personal favorite! Delicious and crisp without being greasy. Mushy peas optional. Stop by Daunt Books when you're done!

I've eaten my fair share of fish and chips in London, the place I keep going back to is the Laughing Halibut on strutton ground near St. James' Park. I've also enjoyed The Golden Hind near Bond Street tube and Poppy's Place (now closed) near Camden Market, there's another location near Spitslfields

try The Golden Hind - it's cheap and cheerful which is code word for unpretentious but good; it is BYO so make sure you bring your choice of poison :) and it is walking distance from Baker Street :) boom boom 

A friend introduced me to Laughing Halibut and it was by far the best fish and chips I've ever had. It's a bit out of the way and a bit grungy but well, well worth it!!! 

I also had exceptionally great F & C at The George | Strand which I ducked into during a rain storm--turned out to be absolutely great!

If you want proper fish and chips, head to Masters Super Fish at 191 Waterloo Road. Its not fancy by any means but its a good old fashioned fish and chips shop and the food is fantastic.

Geales - 2 locations in London for fancy fish & chips, one Geales in Notting Hill and the other Geales in Chelsea.

Best place by far is The Seashell of Lisson Grove, not far from Baker Street. They have been serving traditional fish and chips for 40 years. Often a place to spot celebrities.

Enjoy, I'm sure you will.

Micky's Fish & Chips in Paddington! 29 Norfolk Pl, London W2 1QH
020 7723 2384

London won't blow your mind when it comes to fish and chips. For that you will need to get closer to the sea...Brighton (England) is easy to get to and there are plenty of other things to do there.

A Chinese called Phoenix Palace is well frequented by Chinese, usually a good sign and in this case, it really is. Not the cheapest, but worth looking up for a really good fresh meal.

http://www.phoenixpalace.co.uk/

Closest good fish n chips to there - head to Camden for Poppy's Place, or in towards SoHo for really good chips especially - a place called The Rock & Sole Plaice on Endell street, worth the trip if you want properly good FnC.

Theres some great recommendations on my site livemapp.com for restaurants in that area,

Enjoy!