Well, the bejewelled series are quite good. I like 2 the best from them Zuma is also a good puzzlish game. You might also like World of Goo, and maybe Dracula Origins Hope this helps
World of Goo is good. Also try the games at http://lobstersoft.com. They have several good ones, although Gemsweeper is probably best, its like Picross DS for the PC.
If you are going to gift, give world of goo but there are also lots of free games online, just go to places like www.addictinggames.com or www.kongregate.com and go to the puzzle category. Games like 3D Logic or fantastic contraption are very good. There are also free zuma/bejewled games online
escape from monkey island. you'd love it. it's old, (not ancient) like modern day games but not intensified graphics. not free, it's a 2 cd game, cartoony, puzzles, comedy. great game. i'd play it again if i didn't know about it. has been a long time though so maybe i'll play it again.
portal is a good challenging game (PC is better cause you can download mods) but it isn't as fun the second play through cause you know what to do
