To me your list of speedup software seems overly excessive. I suspect a lot of overlapping functionality within this set.
When you start a gaming session, would it not be smarter to disable (MS Windows and 3rth party) services and other background tasks (indexing for example) that are not essential for the game? Throwing in the famous car analogy...'nothing beats cubic inches'.
Go and look at sites like www.blackviper.com to see which services can be disabled. Besides spending some time this solution is free, unlike all those more or less 'snakeoil' type of software you mentioned.
IMO, those programs are good to cleanup a PC and make sure unnecessary utilities are not running when you don't need them... but they won't really boost PC performance that much until one can feel the difference (normally you will need a benchmark program to see the difference).
Your suggestion of disabling services too has no big effect on overall PC performance... the crucial point is, if one really need to squeeze very bit of extra memory or every bit of other PC components's performance (e.g. hardisk I/O or display), it seems to me that PC is not suitable for gaming.
i.e. if one has a PC which is good enough for average gaming requirements, those efforts of tunning is not worth the small performance gain.









