For me, it depends on the platform.
If you are using a Mac:
Final Cut Pro. Hands down. No other Mac program beats it. If your serious about your videos, get this. Hell, if your rich, I would tell you to buy a Mac just for this.
If your using a PC:
Avid Media Composer is the way to go for me. Powerful features but steep learning curve. Knowing your way around is essential. Not to mention it comes with a price tag that is off putting to some. [Edit] I should also put it out there that this is the de facto choice for studio professionals. Not that it matters with your personal opinion but that does carry some value.
Also, I find that Adobe Premiere Pro is very solid and a good intro into professional editing programs.
If you cannot shell out the money or find some way to get Avid or Final Cut Pro, Vegas Pro is fine. I would say 8/10. It does miss out on some of the more powerful functions.
If your using Linux:
Your stuck. I have not seen any good ones.