I'm looking to buy a laptop that will work for allround purposes with a little bit of gaming and lot of photoshop and video editing involved.
Most importantly I need it to last for the next three years without becoming too obsolete..so in this context which is a better processor?
The Core i7 720QM or 820QM would be the best processor. If you're concerned about battery life though, you might like to consider the Core i5 400M or 500M series. If you just need portable raw power, go for the i7 QM series, don't go for the i7 620M, it's essentially a Core i5 500M with a bit more cache and a bit higher clock speed.