Here's a trick from Windows 7 - for things you want to run on startup with admin privs use the task scheduler to launch them. It's possible to run them with the highest privileges and with no UAC prompt. See
http://www.techrepublic.com/blog/win...-scheduler/616 for an example which still applies today. Software can programatically set this up for you and so it's really down to the authors not being compliant with the security model (for example, CCleaner used to hit UAC but they've now fixed it).
For stuff you run manually, and only on occasion i'd advise you live with it - after all it's there to protect you and whilst not bulletproof it's an extra level of protection nonetheless. I'm a developer and I run UAC at default level on all my systems (and i've even made our own software compliant with it too).
If none of that helps there is one other trick..