Hercules: The Legendary Journeys
Xena Crossover Episodes

First Season
The Warrior Princess
Xena, a mighty warlord, decides that Hercules represents a serious threat to her plans of conquest and decides to kill him. In a devious plan, she ensnares his best friend Iolaus in a web of sex and lies, and then turns him against his friend. Realising the danger he's in, Hercules tries to rescue him, thus falling straight into Xena's trap.
Episode: 1.10, US airdate:
Guest Star: Lucy Lawless (Xena).

The Gauntlet
Xena's army runs riot while she's away and slaughters all the inhabitants of a small village on the instructions of Darphus, her lieutenant. When she finds a baby in the burning rumble and refuses to let him kill it, Darphus denounces her as weak and forces her to undergo a brutal ritual of death called The Gauntlet. When she expectedly survives it, she is banished and wanders the land... deciding that bringing back the head of Hercules would re-establish her position with her army, she sets off to kill him. However he defeats her yet lets her live, encouraging her to help him stop Darphus' bloody rampage across the land.
Episode: 1.12, US airdate:
Guest Stars: Lucy Lawless (Xena), Robert Trebor (Salmoneus), Matthew Chamberlain (Darphus), Dean O'Gorman (Iloran), Peter Daube (Spiros).

Unchained Heart
When Ares resurrects Darphus from the dead, Xena teams up with Hercules and an extremely suspicious Iolaus and together they try to stop him and his evil. Soon they discover that he is feeding the victims of his bloody conquests to Graegus, Ares' man-eating pet, and must try to destroy the monster before it gains in strength and enables Darphus to rule the world.
Episode: 1.13, US airdate:
Guest Stars: Lucy Lawless (Xena), Robert Trebor (Salmoneus), Matthew Chamberlain (Darphus).

Third Season
Surprise!
Hera frees Callisto from Tartarus on condition that she attempts to ensnare and kill Hercules. Posing as a grateful widow rescued by Hercules, she infiltrates a party for his birthday and poisons all the guests including Iolaus, Alcheme and Iphocles. Assuring Hercules that the apples from the tree of life are the only way to save them, she and Hercules go in search of them. Reaching the chamber, she tries to trap Hercules and then eats one of the apples making her an immortal. Hercules escapes and turns the tables, leaving Callisto trapped in the burning remains of the temple.
Episode: 3.?
Guest Stars:: Hudson Leick (Callisto), Liddy Holloway (Alcmene), Kevin Smith (Iphocles).

Judgement Day
Overhearing a conversation in a bar, Xena and Gabrielle decide to go and visit Hercules and his new bride. When they get there, they discover that he appears to be the prime suspect in her murder. Working with Iolaus they struggle to prove Hercules' innocence and soon realise that it's a plan cooked up by Ares to get his half- brother executed. Soon it's up to Xena and Gabrielle to trick Ares into revealing his involvement and thus Hercules' innocence.
Episode:: 3.?
Guest Stars: Sam Jenkins (Serena), Lucy Lawless (Xena), Renee O'Connor (Gabrielle), Kevin Smith (Ares), Joel Tobeck (Strife).

Fourth Season
Stranger In A Strange World
Hercules and Iolaus are fighting to free a princess captured by a gang of mercenaries when the leader drops dead unexpectedly in front of their eyes. Things hot up when Ares arrives and is very angry with Hercules for having killed his protege and starts a fight. Aphrodite then turns up with the news that Zeus is dying, but Hercules and Ares carry on fighting anyway. Taking their fight outside, Zeus finally intervenes with a thunderbolt openning a mysterious vortex through which a jester appears followed by a group of horseman, the horsemen grab Iolaus and return through the Vortex. Iolaus wakes to find himself dressed as a jester and at the beck and call of an evil Hercules sporting a goatee beard. This Hercules he comes to learn is known as the Sovreign and is holding the gods of Olympus hostage while he slowly poisons Zeus. Seeking the secret of the poison, Iolaus encounters a very different Xena who is the mistress of The Sovreign, and a very different and demur Aphrodite! He even meets the leader of the resistance effort against the sovreign's rule -- Joxer! Discovering that his alter-ego, the jester, was about to kill Hercules Iolaus is faced with the impossible decision as to whether he will kill the Sovreign to free these people and save Zeus, in the knowledge that in doing so he will kill his best friend, Hercules.
Guest Stars: Lucy Lawless (Xena), Ted Raimi (Joxer), Kevin Smith (Ares), Alexandra Tydings (Aphrodite), Renee O'Connor (The Executioner).

Prodigal Sister
Hercules frees a group of slaves and then decides to help one of their number, who is blind, seek out his long lost sister. As they head for the docks to board a ship to his homeland, they meet Ephiny - Queen Regent of the Amazons and her centaur son, Xenan. Hercules is shocked when his companion tries to attack Ephiny when he hears that she is an Amazon. He discovers that a rogue group of Amazons is responsible for the attack that blinded the young man and seperated him from his sister. Travelling back to his former home, they are attacked by the Amazons and captured. Hercules is forced into a fight with the evil Amazon Queen during which time he notices that one of the Amazons wears the same tattoo on her hand as the young man - his sister.
Guest Stars: Danielle Cormack (Ephiny), Reece Rodewyk (Xenan)

Armeggedon Now
As the flames reach for the skys at the funeral of Xena and Gabrielle's children (see Maternal Instincts) - Hope and Solan - one particularly group of sparks forms into a coherent grouping and makes its way to a small town. In a dark alley, the figure of Hope reforms out of the sparks and immediately kills an old man for his cloak. She later goes and free Callisto from where Xena trapped her and enlists her help in her latest scheme, which is to dispose of Hercules by killing his mother before he was born. Callisto pays a visit to Ares' temple and in the ensuing events kills Strife using the Hind's Blood dagger, and is then sent back in time by Hope. Shocked and scared by Callisto's actions, Ares agrees to help Iolaus save his half-brother Hercules and sends him back in time too. Reaching Alchemne first, Iolaus tries to pursuade her to go into hiding with him, but she refuses and all too soon Callisto appears...
Guest Stars: Hudson Leick (Callisto), Amy Morrison (Hope), Kevin Smith (Ares), Joel Tobeck (Strife).

Armeggedon Now II

Fifth Season
Sky High
Hercules and Ephiny join forces with a centaur and a man accused of murder to try to stop a community being destroyed by an erupting volanco.
Guest Stars: Danielle Cormack (Ephiny)

s1e08 Prometheus
s5e12 God Fearing Child

больше не помню, хоть убей... народ, помогите!

Герк не в 3х, а в 2х эпизодах появлялся.