I'll throw in my few cents as I made the move to mechanical about 6 months ago after having numerous rubber dome "Gaming" keyboards and nothing compares to the pure joy of a good mechanical one.
The one I'd like to recommend is the Corsair K70 with Cherry Red switches. Whilst it's quite pricey, currently sitting at around £100, its a cracking all metal, back-lit full mechanical keyboard with its raised keys and excellent feeling every key stroke.
The Cherry Reds don't make that click noise, but you do get a satisfying clank when you type with this thing. Its pretty loud but feels fantastic to type and play on. There is also the K65, which is slightly cheaper but doesn't have a number pad nor does it come with the wrist rest like the K70 does.
Gaming wise I've noticed a slight improvement to scores, but now my finders don't ache after a long session like they do on, what seem now, hard to push down keys of a rubber dome board. In terms of typing I've gone from 70 words per minute to the top end of 90, as your fingers just glide over it when you get used to it.
