Quote: "Picked up a GTX 460 on e-bay for £21 (all I can afford), but O.M.G! I am blown away by the difference in performance. I can play just about anything now with details maxed out."
lolol clearly you don't play many modern games then!

Not to say it's not a worthy upgrade... I mean your CPU would be the bottleneck if you went any higher with your GPU, and ANY dedicated GPU is going to be way way better than an integrated chip
My graphics card history is this (counting the first PC our family ever owned since my brother and I always used it for games):
-
Nvidia Riva TNT 2 32MB (and once we figured out we could install PC User's tweaked Omega drivers, boy did that ever improve stability on Windows 98! We used to push that little card right to limit, playing games at 5fps because we were so young and just loved games

)
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Nvidia GeForce 9400GT 512MB (first new PC I ever bought... only 2009 so not long ago)
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AMD A8 APU (forget exact model, had dedicated GPU chip, came in laptop, caused me to never want AMD ever again)
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Nvidia GeForce GTS 250 1GB (my brother's after he upgraded - I'm older than he is but he always buys PC upgrades before me)
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Nvidia GeForce GTX 470 1GB (again, my brother's - an absolute monster of a card, it was, genuinely sounded like a jet taking off when you pushed it hard and regularly ran at 80+ degrees C)
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Nvidia GeForce GTX 560 1GB (bought from eBay - ASUS DirectCU edition)
-
Nvidia GeForce GTX 760 2GB (bought from eBay - pretty plain Palit edition, basically reference, but a very good card and well worth the upgrade!)
My brother currently uses a GTX 770 2GB (Gainward Phantom, very cool card!) and it's only slightly better than mine. Generally he manages to find better settings for our games before I can, and then I just copy his settings.
Next upgrade for me will either be a decent case with a side-window (still using my very plain Thermaltake WingRS 101 from 2009) or an i7 K-edition (currently got an i5 non-K) with an aftermarket cooler (possibly liquid).