I'm using Contacts Sync for Google Gmail (Mac App Store) because I couldn't get the built-in sync to work properly or reliably.
For photos I'm using Dropbox. I can't imagine giving up iPhoto for Picasa (desktop), but right now it's less than ideal.
I also purchased Sparrow for Mac, which I love because it means everything looks the same on my desktop as it does in Gmail on my phone.
For music, I'm debating between letting Google Music transfer my iTunes library online, or using Spotify. I have a fair number of Apple Lossless files which won't sync via either, so I need to convert everything first. Mostly, I just use Spotify Premium.
Would love some advice on two-way syncing photos between iPhoto and Android.
The best option would be to sync your files with Syncmate. You can sync different file types on differnet platforms. Files such as music, videos, contacts, images can be synchronized on different platforms including Mac, Windows Phone, Blackberry either through a USB Cable/ Wi-Fi. It's awesome, I tried it already. More info: Optimum Systems: Mac Sync Software