Chinese: especially on airplanes. They have no problem smoking multiple cigarettes in the lavatories and stinking up the whole plane.
Russians: I didn't see much of a problem with them during their hey day (before the ruble tanked in 2014). But when they got drunk bad things tended to happen.
Israelis: Really? I've only came across maybe 2 during my travels. And one was a female that worked at the Tiger Temple outside of Bangkok.
Well, maybe I just happened to be that unlucky guy that bumped in to the bad apples.
My comment is also the general feeling that the people around me where I lived was having. When I was training Muay Thai in the summer period of 1998-2004, I was living at a friends place that was having his own land and renting out 20 small houses in a walled area for long-term stayers. And when you live that close to each other, you also notice people who come and stay for 2 weeks, first timers, the kinky guys going for kaoteys etc. And by this, you also notice the different feature that each country will provide. A lot of this knowledge I got from my late mornings at the pool after running, and to relax with the people staying long term. Dive-instructors, bar-owners etc. And they all provided me with insight only they could know.
For instance. My friend who is the owner of this bungalow park, asked me for a favor, becuase he didnt have time that day and he had to go to Malaysia for a 1 day trip to renew his Visa. I was going to pick up 2 Italians from the airport and help them out with the room, and show them a good place to eat at the evening. They didn´t know any language than Italian and i just happen to speak portuguese, so we communicated that way. The 2 gentlemen were first timers and really really sweet guys. The evening came and I drove them to a nice fish restaurant and they got pretty wasted. I told them I wouldn´t drink with them nor would I go out and party. But they were really persuasive and I promised to follow them to one of the Red districts and pimp up 2 girls for them. I told the girls they didn´t know any english and they just wanted to have sex, and the only things the girls had to do was to smile and make them feel good the rest of night out.
In the morning after my morning run and skipping, I was called to the house the Italians was living in. The girls seemed very upset and I asked what was going on. Then came the story. The girls wrote 1000 bath on a note, and the men did recognize they wanted money. But for what? The men was at this moment in full swing with their Italian body language and yelled puta madre that and fanculo that. They told me they gave the girls free alcohol all night, gave them food and even bought a teddy bear for them. And now they are asking for money??! At this time I started to laugh, I coudln´t control myself. And then I told them to give them the money. It´s the way of living for some of them. But the men were pissed the rest of the day, but enjoyed the rest of their stay.
This is one example of many that I have had with different nationalities. And the treat with Italians is that they really think they are the Gods gift to woman. I just happen to like them, very funny people!
The russians I have met at Koh-phangan, Samui, Samet, Pipi, Phuket and Pattaya have had a tendency to show they are very important people, and humble act is something they don´t possess. Individuals I could handle because I met them at camps, but couples were the worst. And the woman was always the really bad one. Acting like queens with a lot of money. Do they smile and ask politely? Not in the Thai-world.
The Israel comment is more narrow minded from my side, because I have only met the younger male part of Israel. All of them disharged from military and going for a long holiday. And all of them in an enclosed area. Namely at the MT-camps. Farangs going to Thailand for the art of Muay Thai are usually the ones who shows most respect for the cultural aspects surrounding it. So it angers me when young brats who think they own the world come and pay their money to be supervised and then stop doing what the trainer is asking and question it, and slowly start to make their own Krav maga show?? What the hell going on? I don´t give a rat ass if your style is effective in combat. Zero respect. Not all people came to do Krav maga show, but the attitude.... that they own the world is still there lurking under the surface.
So my personal experience is that I am not so fond of young Israeli male soldiers going for holiday in Thailand.