I have several pc games on hard disk (e.g, Bioshock, Oblivion, FEAR, and Tomb Raider: Anniversary; Underworld; and Legend. I've tried steam before, Team fortress 2, Black Mesa.
I've considered buying from steam, however the prospect of buying a license to play as opposed to a physical hard copy doesn't sit right with me. Is installing and buying games from steam worth it?
For games you can't get on CD I don't see why not.
Yes because with some games you have to have steam anyway.
I was in the same boat as you. Try it, experience your first steam sale, you'll see what we have all been talking about.
It's unsettling to purchase something and have no disk to show for it, but you quickly get over it, once your Half Life game saves sync across computers in real time. That actually caught me off guard, and was one of the reasons I fell in love with Valve
I understand where you are coming from, having a collection you can point to is a great feeling indeed. But even leaving aside the price issue (see steam sales). The amazing variety, great support, and monstrous community has made steam more than just a place to get games from. Its a cool thing to be a part of.
As for the license issue, well... its a good problem to have. You can't have a game installed on more than 5 PCs at a time, but you can change what 5 PCs are allowed to have your games with a single click, so its not really a problem. After 5 or 6 years I've never had an issue of not being able to access a title I own (not counting an issue with EA... because EA).
I was skeptical of the whole 'cloud' thing for a long time. But after getting comfortable with it, and seeing all the ways it can make life better I'm not sure I'd be willing to go back to the old way of doing things. It just works more smoothly.