My favourite game genres are RTS (real time strategy) and Space MMORPGs (Massively Multiplayer Online Roleplaying Game). I usually play using the pseudonym "boolybooly".
I am currently betatesting 'Earth And Beyond' for Westwood and Electronic Arts. There are a few thousand of us registered to do this and every evening (GMT) hundreds of us gather to play in the MMORPG virtual world which Westwood programmers are creating bit by bit. Its a lot of fun to play and a fascinating glimpse behind the scenes of a first rate computer game production company.
Jumpgate is another particularly fascinating Massively Multi-Player online universe game which I have been priviledged to be able to beta test. It involves flying a ship and forging a career, not unlike Elite which this genre of game often claim as an antecedant. (Which, for the initiated, I played in the '80's on a BBC B to Elite status). Jumpgate or JG has now been published and is available to play (on a pay as you play basis).
Of the existing RTS I like Homeworld and Dune the best. Homeworld and its successor Cataclysm I like because it is the best graphically developed and most 3 dimensional RTS series I know of. Dune is interesting because it was the theme of the captivating SciFi books by Frank Herbert.
Prominent among RTS is Empire Earth by Stainless Steel Studios, which is a terrain based 3D RTS with an enormous scope of play not least as the civilisation design spans over a dozen epochs (14 in fact). I was a betatester for EE, and contributed to the design of EE at appropriate forums and even won prizes from the designers for my suggestions over the two years prior to its publication. So this is a favorite of mine and has a special place on my hard disk drive.
I am also interested by galactic conquest sims like Master of Orion II and Pax Imperia, Imperium Galactica II and most recently Space Empires IV. I am looking forward to the release of Master Of Orion III sometime next year.
Games help to develope the display technology and user interfaces for computers considerably. As such I believe they have an important place in the high tech economy, and are more significant than being simply a frivolous extra.