Why probes and satellites?

[SelectHalfling0]

Lol, I've got an old post in this thread, however I know what you mean by things have drastically changed @Renegrade. No longer do I use comsats, but now tedious missions and missions to Eve are done entirely by probes.

[Hodari]

Much lower mass and the fact that you don't need to return a crew back home means you can go a lot further with a probe than with a manned mission, especially in career mode before you've unlocked everything and while resources are still limited.  By the time you can barely get a crew to the Mun and back, you can probably do at least a fly-by of almost anywhere else and easily get all the science you need to unlock the rest of the tree.

The much lighter mass also makes them better for ion engines which even further increase their range advantage.

From a realism standpoint, it makes sense that you would want to send unmanned probes someplace before trying with a crewed mission.

In the stock game at least, probes and satellites might be worthless early on(one of my biggest complaints about the current tech tree), but they are very useful in the middle-game stages.

[Choctofliatrio2.0]

Main Reasons:

Lighter, cheaper, failure is less disastrous

Also, another important reason (for me, at least), is that I think a well-built satellite looks awesome. I've never been able to make a crewed capsule look good. Parts like science gear are always awkwardly sticking out. But on a probe it just looks right. 

[Xavven]

I realized this thread was necroed as soon as I read @Alshain saying "I'm kinda new myself". I read that and was like "whaaaat?"