What is the best Garmin Forerunner watch for running?

I have owned a Forerunner 305, 405, and 610.

Overall, all of the GPS watches in the series deliver comparable data-gathering performance: time, pace, distance, location. Thus, choosing between them comes down to comparing comfort, ease of use, and price.

Garmin Forerunner 305
Pros:

• Controls are done via physical buttons, so adjustments (i.e. turn off auto-lap) are easy to do mid-run.
• No ANT stick to lose
  
• Cheapest (but it has been discontinued by Garmin)

Cons:

• Super freakishly large
• Slower to pick up satellites than newer models
  

Mode of failure:
I exchanged one which was under warranty because the battery stopped charging. The second one possibly died from corroded charging contacts

Garmin Forerunner 405
Pros:

• Sleeker form factor than 305; better for small wrists

Cons:

• Touch-bezel is not very responsive, and its operation is not very intuitive
  
• Need to keep track of ANT stick
• No way to turn it off completely
• Charging system (spring loaded clamp) is ill-conceived and finicky

Mode of failure:
The ill conceived charging system corroded the contacts on the watch so it wouldn't charge anymore

Garmin Forerunner 610
Pros:

• Even smaller profile than the 405
• The touchscreen is responsive and intuitive. It works by pressure rather than by conductivity, so it operates with sweaty fingers or with gloves.
• You can turn it off completely
• Magnetic charging base

Cons:

• The ANT stick is the tiniest thing ever

Conclusion: I am really liking the 610 so far, but whoever designs these watches should consider that runners' wrists are covered with sweat and possibly sunscreen, and consider placing the charging contacts accordingly.