Followers of the Viral Video Chart‘s global ads chart have certainly been put through the emotional wringer this month. Rather than the usual bombardment of funny branded videos, May has seen a number of videos that have left many users with lumps in their throats.

None more so than this very poignant PSA for the David Cornfield Melanoma Fund, which was the most popular video in May, with over 263,000 shares across Facebook, Twitter and the blogosphere.Called ‘Dear 16-year-old Me’ and created by small Toronto agency, Evidently, the video features real people addressing their younger selves about their heart-breaking struggles with the deadly skin cancer. These include melanoma survivors, family members of those affected by the disease and physicians.

Anything video that elicits an emotional response usually performs strongly, and “Dear 16-year-old Me’ does that in spades – despite being over 5 minutes long.

It is not the only video that has been tugging the heart strings. Google last month launched a series of Chrome commercials as part of one of its biggest ever ad campaigns, with three making it on to the top 16. The first was a supportive video for LGBT teens which compiles some of the most inspirational clips from the “It Gets Better” YouTube channel – a project started by gay rights activist Dan Savage.

People featured include Lady Gaga (who also stars in another Google Chrome ad at number 11 in the chart), Ann Hathaway and even Woody from Toy Story. The ad attracted 38,843 shares across Facebook, Twitter and the blogosphere during May, making it the 14th most shared ad last month. This is not the first time Google has backed the campaign publicly, with several of the search engine’s own LGBT’s employees doing their own video.

Two positions below it is another Google ad designed to make you well up inside. Called “Dear Sophie”, it shows a father using Google products, such as Gmail and YouTube, to catalogue his daughter’s life, so they can share it together when she is older.

But just when you thought this emotional rollercoaster was about to stop, another PSA punches you right in the heart with its furry, cute paws. “I Want”, created for the Animal Humane Society, was the 12th most shared ad in May with almost 52,000 shares. It literally gives cats stuck in one of their shelters a voice (particularly cute ones) as they explain that all they want is someone to love them.

It is not hard to see why it is so popular. Combine some sad stories with cats, which seem to have their fishy paws all around the throat of YouTube, and it does not take a zoologist to know you have a hit on your hands.

Thankfully, the latest Call Of Duty: Modern Warfare 3 reveal trailer offers some welcome relief from this emotional anguish. The second most popular branded video last month – despite being released on May 24 – the video is the first real look at the highly-anticipated game from Activision, not due for release until November 8.

Another video which literally captured a lot of attention last month was a breathtakingly simple video created by a bunch of Canadian camera shop employees over a weekend. In fact, their boss, Julian Ferreira, knew nothing about the video until the following Monday when he was presented with a rough cut of “Battle At F-Stop Bridge”, a wry send-up of every war movie you have ever seen, with cameras and flashes replacing machine guns and grenades respectively. A fortnight later, and it has attracted almost 1.3 million views, putting it in sixth in the chart.

Other branded videos which made waves last month was a controversial PSA which used the assassination of Osama Bin Laden to inform people of the dangers of not buckling up and an ad for Justin Bieber’s new perfume line “Someday” that, well, just stinks.

The Sweet Sixteen

1. “Dear 16-year-old Me” – David Cornfield Melanoma Fund – 263,721 shares

2. Call Of Duty: Modern Warfare 3 Reveal Trailer – Infinity Ward – 220,211 shares

3. The Force – Volkswagen – 99,220

4. Royal Wedding – T-Mobile – 97,007

5. Osama’s Watery Grave Captured – Seat Belt Awareness – 79,337

6. Battle At F-Stop Ridge – The Camera Store – 72,287

7. Someday Perfume – Justin Bieber – 56,500

8. Is Tropical – The Greeks – 55,592

9. Strangers, again – fff – 53,894

10. Roller Babies – Evian – 50,777

11. Lady Gaga – Google Chrome – 47,448

12. I Want – Animal Humane Society – 42,396

13. Ken Block’s Gymkhana 3 – DC Shoes – 41,025

14. It Gets Better – Google Chrome – 38,843

15. Danny MacAskill: Way Back Home – Red Bull – 38,104

16. Dear Sophie – Google Chrome – 37,205