STEAM
For People who say they use Steam and have no issues with it, maybe they don't realise that they cannot resell their games - any game that has to be registered on steam cannot be sold afterwards (unless you sell your entire Steam account with it, which is against Steam Terms and conditions and would result in the entire Steam account being cancelled for the unlucky buyer - don't buy a Steam Account!). Nor can you un-register a game from Steam, it's registered to you forever (or rather, until they decide to close down the Steam servers, then your games are useless).
SECUROM
SecuRom is an abysmal piece of software - It has screwed up backups of my Windows Vista system numerous times, and I can't get rid of it - even with SecuRom's own removal tool. And if you remove SecuRom (and the registration details with it), then you may not be able to play the game again on any PC.
Securom is MALWARE; it is installed without your knowledge or consent; it is difficult if not impossible to remove and can screw up proper security of your system - and again, I believe once the game is registered you can't resell.
Both SecuRom and Steam are, yet again, security measures that PENALISE HONEST PEOPLE who actually pay good money for their games, in order to avoid piracy. But they go further than that. They are both mechanisms for boosting sales by preventing the sale of used games. Don't go near either if you plan to resell your game afterwards - you won't be able to.
I will not buy any game that requires either a Steam account or Securom. Whether or not you do is your choice, but I would urge people not to: Don't buy ANY game which requires SecuRom or Steam and be aware they don't always tell you - you have to find out yourself - always ask before you buy.