It's obvious that one of the series' plot threads is how Po and Tigress become closer friends, setting the stage for them to become more. Hence, the show gaining an entire page devoted to the Ship Tease moments.
The Princess and the Po: Po bets Mantis and Tigress a foot rub that he'll get the princess to like her. Tigress (who is sure that Po will fail) seemed all too eager to say yes.
Could also be seen as her looking forward to a chance to see Po embarrassing himself. Occasionally, Tigress isn't above being a bit vindictive to Po or a few of the other Five (namely Crane, particularly in Scorpion's Sting).
Sticky Situation: Tigress actually playing Hide and Seek with Po even though she could have just ignored him. Later: "Did you think I wouldn't find you?"
Earlier than that, when they're chasing the Croc Bandits Good Po flirts in a more friendly way when he says her fur looks nice. She simply says to hurry up, as if she were saying, "Not now."
Master Ping: Tigress falls asleep on Po's shoulder. She accidentally slugs him when he wakes her up, and then promptly falls asleep on his shoulder again.
Granted, Po is also the only one she could easily fall asleep against without knocking them over or squashing them.
Ghost of Oogway: While Po convinces all the Furious Five to be lazy, it's Tigress who takes it to the extreme in that she won't even use her hands to eat.
Tigress is also the most dedicated, hardcore student amongst them and is the most unwaveringly loyal to Shifu, following his orders to the letter and taking it Up to Eleven. In this case, Shifu had ordered them to heed Oogway's judgment, and that's what she did. It is far more likely that it was either Rule of Funny or a show of her being the devoted student she is.
The Kung Fu Kid: One of the things that makes Po jealous of Peng is that he managed to make Tigress laugh.
Ladies of the Shade: Tigress isn't exactly trusting of the performers, one speculation could be that she's jealous.
However, in the same scene the Five lampshade the fact that Tigress does not trust anyone, not even the mailman who has come to the Jade Palace for thirty years (or, as Tigress said, "planning something for thirty years"). Tigress' distrust has been turned into a Running Gag in the show (such as her mistaking being approached with a towel as being an assault).
In With The Old: When Po is packing everybody's stuff and for some reason tosses Tigress out of her room, he is so anxious that he grabs her shirt... by the chest. She seemed angrier at being thrown out though, as when he grabs her shirt she just seems surprised. She does threaten to kick his ass though.
Father Crime: At the beginning of the episode, Po outright tells Tigress he wants to be closer to her.
Enter the Dragon: Tigress's reaction to Po's Disney Death is...quite something. Her reaction when he is restored by the peach sprout (which is almost identical to the "Owl Be Back" example with Shifu below, only far more effusive), is also heartwarming.
Midnight Stranger: Tigress is infatuated with the Midnight Stranger (who is actually Po), describing him as, "A ruggedly handsome lone wolf, living by his own rules, answering to no one; waiting only for his true love to come along and tame [him]." She even wears perfume and waits in town to meet him. When she finds out who he really is, she leaves to throw up; which makes her usual response of leaving to work out sound more suggestive.
For obvious reasons, the episode "Bride of Po" pretty much has a field day with this.
Jailhouse Panda: Po tries to invokeSomething Only They Would Say but can't get Tigress and Monkey to stop attacking, so Po outright says that Tigress had a crush on Shifu as a teenager. She promptly stops and realizes it's him.
Ladies of the Shade: Invoked by Song, who dates the oblivious Po in order to gain his trust, however she ends up Becoming the Mask and begins to genuinely care for him. Po even claims she "gave me an owie on my heart" when he learns that she's a thief. Also noteworthy is the fact that she kissed him on the cheek and he looked anything but conflicted and/or displeased.