Remote desktop isn't $50 - not sure where you are getting that from... I've attached a cab (unzip first)... You can do anything on your computer that you would normally do while sitting in front of it (short of playing a 3d game). Turn on high color and full screen it in landscape mode for best results...
Slingplayer is awesome, I get great results and it isn't choppy if you even have semi decent evdo signal strength...
Palringo also has push to talk support if your friends run it also (it will also send a link to a wav file if you send voice to someone on aim or something)... It also has some cool location stuff where it will broadcast your location if you turn it on to others using palringo.
Google maps will find anything and everything you want to find and has satellite views and stuff, but it's really great for looking up a phone number or location - a definite must have and it's free
http://www.google.com/gmm . Garmin on the other hand has turn by turn directions similar to the sprint app, but there is no monthly service fee and it has traffic and stuff (not sure if the sprint one does, I haven't used it). Garmin also doesn't need a data connection on the whole time, so you can use it while you are talking on the phone/etc (it only needs data if you want to download traffic or use it's built in google local searching etc). There's even a regedit to make sounds still work while on the phone - it will come out a bluetooth headset if you are using that too. I use google maps when I want to find or call something and garmin when I want turn by turn directions to get there...
Can't comment on the music player since I don't use my phone to listen to music...
Live search's database seems to be far inferior to google's so I find it is often harder to find stuff off of. The info seems more outdated too...