well if the bike you've got can fit 22s and you're not running with mudguards, generally you could fit 25s no problem and not have any fork/frame clearance issues. Even the very narrowest of rims would be fine with a 25.
If you're light then a 23mm will do for almost any occasion but depends on if you want comfort over weight saving? A 25 at a slightly lower pressure might still have a similar rolling resistance as a 23 but offer more comfort and certainly opens up a wider range of choice of tyre.
There's bags of cheap new tyres out there if you look for them. I just got 2 new Michelins for £10 from Chain Reaction but that was the last.
You can get all black Vittoria Zaffiro tyres for £6.60 from Parkers http://www.parker-international.co.uk/1 ... gn=pid1993
1958 Carlton Super Python
1990's Gitane VITUS GTI Triple Butted
1996 Raleigh Titanium Special Products Division
2007 Specialized Globe Pro
2007 Specialized Globe Expert Ultegra 6700
KTM Strada 6000 Carbon Dura Ace 9000