I am mostly familiar with old-school console games like Nethack and Dungeon Crawl Stone Soup. However, that is not the limit of my expertise. Indeed, I am also somewhat knowledgeable about The Legend of Zelda(Although I may not be alone in this regard.) series, with an emphasis on OoT and GBA Zelda Titles.
I also enjoy pokemon games, and prefer Pokemon Green for the Game Boy Advance. Although, I admit that I haven't played Green in a while.
If your question involves more recent games like MW3 and/or Mass Effect, then my answers will be limited to common-sense applications of general game strategy, as my experience with these games is consierably more limited.
Thank you for visiting my info, and I hope I can help you! :)