I certainly like Tsunderes (evident to who looks at my moe list). They usually are strong willed which is a characteristic that I admire. Some are actually very weak inside or can have some moments of weakness which is a likeable characteristic to me too (that's when they start to give you "protect me/help me" vibes). Their "violent" nature can be understandable as they having difficult to express they fellings (as long they are not too violent) which get some compassion from me. Their usual shy/unable to know what to say/embarassed reaction to those that show affection to them (whenever it's love or friendship) are very likeable and moe! Another plus is that they usually have a strong sweet and caring side to a few people that they think that deserve it and tend to be very loyal to these people.
Now I usually don't like tsunderes that are very violent but how violent they need to be to get my dislike depends on the setting and to who they're being violent. If the setting is more fighting oriented I may overlook more their violence (in a fantasy like setting I may not mind a level of violence that I would mind in a normal school setting). The nicer the character who the tsundere is being violent to and the less he deserve it at the time the less violence I will tolerate. So an example of Tsudere I really disliked was Taiga at the beginning of Toradora (but she totally redeemed herself later).
Now to give an example I would choose Tohsaka Rin that is IMO the best tsundere I know (and one of the most moe ones).She's very, and I mean really very, strong willed as you can see by many of her scenes especially in some scenes in the HF route of the VN. And she's actually very gentle (even if she doesn't show it) and caring even with people she doesn't know (but she's merciless with her enemies). You can see that in the prologue of the FSn of the VN's as you play with her POV. And she have some very moe moments. If anyone played the UBW route and are a Rin fan than you should remember of the scene where: