I use Quicken Home Inventory Manager; it comes free (sometimes) with Quicken's personal financial management software. I'd rate it somewhere in between an Excel spreadsheet and NM Gun Collector. Here's a screenshot:
On the plus side, the whole point is to keep all your personal property information in one system. Think if Rita had stayed a Cat 5 and run straight at Galveston/Houston. You need a record of ALL your belongings. A single database is good.
The biggest drawback is that it isn't easily portable. Ninety percent of the PCs in the world can read an Excel spreadsheet. Ya gotta install Quicken Home Inventory Manager in order to use its data file. (It can be exported to other formats, though with loss of content.)
In my safety deposit box, I keep a data CD and a Quicken Home Inventory Manager installation CD. In that box I also keep an old-school, hard-to-fraud, date-stamped VHS videotape of my property. I refresh these quarterly.
I've been with Allstate for many years, and I know and trust my agent. But if I have a significant, insured loss, I want hard proof.
Life is what it is.