What's a good mobile phone I could buy?

[Verity]

I'm 17, I want a pay as you go phone at a reasonable price, probably £100 at most.
I'd like one with a front camera and decent connection speed, for twitter, facebook, emails and videos. I'm going uni this year, so maybe one that's pretty durable too!

I have no idea at all though can anybody suggest any models?
I'm really thankful for any suggestions

[Landshark]

UK based? Think about getting one of from the Giffgaff network (O2).
You'll be able to let your unused credit roll forward to the next month and also buy 'goodybags' with the amount of minutes and data downloads you actually think you'll need in the upcoming month (those don't roll forward).
See:
http://giffgaff.com/phones

[Yana]

Google Nexus 4 will be a good phone in your price range. Another phone will be Nokia Lumia 900 which is a Windows Phone. These phones are more than decent and will get your job done smoothly and without lags. If you need help buying them at reasonable price and cheaper than retail, mail me.