HOT in London? no way!! It's 75-80 degrees max! (haven't gotten a handle on Celsius yet!) I want my hot east coast summer weather!
It is lovely when it's 75ish here over the summer but it's more like April/May weather.
I've only experienced 2 summers though. So I'm not talking from a lot of experience.
Ah, then you missed the gorgeous hot summers of 2003, 2005 and 2006

. In 2003, it reached 101 degrees in Kent and we had temperatures up in the 90s for almost 2 weeks straight

. I graduated from university in July 2005 and on my graduation day, the temperature was 82 degrees (I was so hot in my heavy black robes that I almost fainted during the ceremony - no air conditioning in the buildings).
In July 2006 we had a 2-week heatwave with temperatures up in the 90s - it reached 97.7 degrees in Surrey on one of the days. I remember getting in my car after work and not being able to touch the steering wheel because it was too hot... and by the time I arrived home 20 minutes later, I had sweat pouring down my back (no air con in the car... or at work, for that matter).
Even the end of June 2009 had a gorgeous week of temperatures in the high 80s/low 90s (however, the hot month of June was then followed by the wettest July on record

). We also had great weather for Wimbledon last summer... two straight weeks of sunshine, high temperatures and no rain at all (normally it seems to rain most of the time during the tournament).
In an average summer, London actually gets 28 days of temperatures above 77 degrees and 4 days of temperatures above 86 degrees.
So, sure, the UK doesn't have the best weather... it is grey and drizzly a lot of the time, but when it's nice, it's absolutely wonderful. When I lived in New Mexico, I really missed the English summer days... it might have been 100 degrees outside in the desert heat, but all I wanted to do was spend a lovely summer's evening sitting outside a pub in England with my friends

.
The thing is, we know our weather isn't that great and that we won't get a long, hot summer like other countries do, but we make up for it by holidaying abroad... there's a reason why us Brits make about 60 million trips abroad every year (45 million of them are between June and August, and 30 million of them are to only 3 countries: Spain, France and the US).
The reason the summers haven't been so great the last couple of years is because the polar front jet stream has been situated further south than normal in the summer months, so instead of all the Atlantic weather systems being deflected north of the US and us getting the hot, dry weather from Europe, the jet has moved further south and so all the Atlantic systems have hit us straight on. Now, whether this has been due to climate change or not, I'm not sure, so I don't know if the recent wet summers are temporary or if they will become the norm.