Harry Potter and the Chamber of Secrets
I'm not sure if this counts as a spell:
"Ron unlocked the cavernous boot with a series of taps from his wand. They heaved their trunks back in, put Hedwig on the back seat and got into the front.
'Check no one's watching,' said Ron, starting the ignition with another tap of his wand."
Then Ron's wand breaks:
"My wand," said Ron, in a shaky voice. "Look at my wand." It had snapped, almost in two; the tip was dangling limply, held on by a few splinters.
After that we don't see him successfully cast a spell for the rest of the year.
Harry Potter and the Prisoner of Azkaban
"Excellent! Ron, you next!"
Ron leapt forward.
Quite a few people screamed. A giant spider, six feet tall and covered in hair, was advancing on Ron, clicking its pincers menacingly. For a moment, Harry thought Ron had frozen. Then –
"Riddikulus!" bellowed Ron, and the spider's legs vanished. It rolled over and over; Lavender Brown squealed and ran out of its way and it came to a halt at Harry's feet. He raised his wand, ready, but –
"Here!" shouted Professor Lupin suddenly, hurrying forward.
He also successfully cast Lumos:
Ron pulled out his wand and muttered, "Lumos!"
A beam of light fell across the grass, hit the bottom of a tree and illuminated its branches; there, crouching amongst the budding leaves, was Crookshanks.
As well as possibly Expelliarmus, although both Harry and Hermione cast it at the same time so it's less clear that Ron himself was successful:
"Expelliarmus!" he yelled – except that his wasn't the only voice that shouted. There was a blast that made the door rattle on its hinges; Snape was lifted off his feet and slammed into the wall, then slid down it to the floor, a trickle of blood oozing from under his hair. He had been knocked out.
Harry looked around. Both Ron and Hermione had tried to disarm Snape at exactly the same moment. Snape's wand soared in a high arc and landed on the bed next to Crookshanks.
Harry Potter and the Goblet of Fire
Ron successfully cast Lumos again:
"Fred and George can't have gone that far," said Ron, pulling out his wand, lighting it like Hermione, and squinting up the path.
Then he used some sort of spell that creates sparks:
"Don' frighten him, now!" Hagrid shouted, as Ron and Harry used their wands to shoot jets of fiery sparks at the Skrewt, which was advancing menacingly on them, its sting arched, quivering, over its back. "Jus' try an' slip the rope round his sting, so he won' hurt any o' the others!"
He casts a Banishing Charm:
"Snape said Moody's searched his office as well?" Ron whispered, his eyes alight with interest as he Banished a cushion with a sweep of his wand (it soared into the air and knocked Parvati's hat off).
Then another Banishing Charm:
"What?" said Ron, his eyes widening, his next cushion spinning high into the air, ricocheting off the chandelier and dropping heavily onto Flitwick's desk.
He casts an Impediment Jinx:
"Good training for when we're all Aurors," said Ron excitedly, attempting the Impediment Jinx on a wasp that had buzzed into the room, and making it stop dead in mid-air.
He also casts an unidentifiable hex, though it's unclear whether it's successful:
He, Ron and Hermione were on their feet, all three of them having used a different hex. Nor were they the only ones to have done so.
Harry Potter and the Order of the Phoenix:
Ron somewhat successfully vanished a mouse:
“She did, however, take many more notes while sitting in her corner, and when Professor McGonagall finally told them all to pack away, she rose with a grim expression on her face.
‘Well, it’s a start,’ said Ron, holding up a long wriggling mouse-tail and dropping it back into the box Lavender was passing around.”
He successfully, although stupidly, casts Accio on a brain in a tank at the Department of Mysteries:
“Honest, Harry, they’re brains – look – Accio brain!’
The scene seemed momentarily frozen. Harry, Ginny and Neville and each of the Death Eaters turned in spite of themselves to watch the top of the tank as a brain burst from the green liquid like a leaping fish: for a moment it seemed suspended in midair, then it soared towards Ron, spinning as it came, and what looked like ribbons of moving images flew from it, unravelling like rolls of film –”
Ron also presumably casts spells in Dumbledore's Army, such as Expelliarmus, Impedimenta, and Expecto Patronum, but none are specifically shown at the time as being his.