Yeah, with ICS, you can disable apps without being root even. I think that is essentially what Titanium Backup is doing when it "freezes" apps. The one advantage of doing it through Titanium Backup is that you can set up filters to freeze/defrost multiple apps at once. So for example, I have a filter set up for any packages that have the words "verizon" or "HTC" in them that I can quickly review what needs to be frozen.
The big ones to freeze, in my opinion, are My Verizon, Backup Assistant, Tell HTC, Verizon Media Manager. These tend to run in the background a lot if you don't freeze them.
Then if you don't use them, you may want to consider freezing HTC apps like Car Panel, Footprints, Friendstream, Twitter trends widget, Stocks app and widget, etc.
Polaris Office, Need for Speed, Let's Golf are also good apps to freeze. Google Talk, if you don't use it.