Square Enix’s official store is running a sale until 15 February, just in case you have nothing better to do this weekend.
There are a couple of rather good deals there. I mean, you could grab every Deus Ex game for a grand total of £5.75, which is pretty good. You could opt for every Hitman game for £7.49. You could even go for all of the Tomb Raider games (barring Lara Croft and the Temple of Osiris) for £14.99. You could even opt for the Eidos Anthology for £23.99, which contains… well, 34 games. Everything mentioned above, plus more.
Personally, there are two that stand out to me, and they’re the two cheapest. The first is Murdered: Soul Suspect for £1.99, because – despite having some slightly ropey stealth – I genuinely like the ghostly murder mystery. The second is the Legacy of Kain Collection, also £1.99, because it’s four Legacy of Kain games and the Nosgoth Veteran’s Pack, and everybody seems to like that series.
Have a look at the sale page over here and see if anything tickles your fancy. I’m a little unsure whether or not that link will work; if not, you should be able to find the discounts by going to the Square Enix store and looking for the big sale banner.