It's made pretty clear that Lockhart is a failure of a wizard, apart from his use of memory charms for which he is quite gifted. In the movie, we regularly see him use a spell which turns out to not be the one he was hoping to use. So my question is do we ever see Lockhart use a spell with the outcome he intended aside from memory charms? I'm open to accepting instances from the movie or books.
Yes, I think so.
On one occasion, at least.
As they entered Lockhart's darkened office there was a flurry of movement across the walls; Harry saw several of the Lockharts in the pictures dodging out of sight, their hair in rollers. The real Lockhart lit the candles on his desk and stood back.
(Chamber of Secrets, Chapter 9, The Writing on the Wall)
We see from a later scene that lighting candles with magic is a relatively easy thing to do. Harry (only in his third year) has no problem doing it by himself.
At eight o'clock on Thursday evening, Harry left Gryffindor Tower for the History of Magic classroom. It was dark and empty when he arrived, but he lit the lamps with his wand and had waited only five minutes when Professor Lupin turned up, carrying a large packing case, which he heaved onto Professor Binns' desk.
(Prisoner of Azkaban, Chapter 12, The Patronus)
It's not a spell but Lockhart may also have brewed the potion that allows you to develop magical photographs. He certainly seemed to have plenty of them around for autographs.
Lockhart seemed to screw up most of his spells. His charm on the pixies didn't do anything and he had his wand thrown out the window. Instead of fixing Harry's arm his vanishes the bones. He fails to defend himself from Snape's disarming spell and drops his wand when trying to show Harry the shield charm. His magical ability certainly didn't keep up with his boasting. But there's no real reason to believe that he couldn't perform basic spells; he wasn't a Squib. Indeed, his ability to perform a good Memory Charm shows that he had a decent level of magical ability, even if he only really cared about perfecting the one spell he needed to claim the achievements of others.
Lockhart can cast other spells
I'm unaware of any instance in the books or movies where Gilderoy Lockhart successfully casts a spell, beside perhaps a Memory Charm. However, there are some examples in other canon material, which at least prove that Lockhart can cast other spells. According to his Pottermore entry:
Sorted into Ravenclaw house, Lockhart was soon achieving good marks in his schoolwork, but there was always a kink in his nature that made him increasingly unsatisfied. If he was not first and best, he would rather not participate at all. Increasingly, he directed his talents towards short cuts and dodges. He valued learning not for its own sake, but for the attention it brought him. He craved prizes and awards. He lobbied the Headmaster to start a school newsletter, because he liked nothing better than to see his name and photograph in print.
Never very popular, he nevertheless achieved his primary goal of school-wide recognition through repeated, attention-getting exploits. He received a week’s worth of detentions for magically carving his signature in twenty-foot-long letters into the Quidditch pitch. He managed to create a massive, illuminated projection of his own face, which he would send skywards in imitation of the Dark Mark.
It would seem that Lockhart can create a holographic image of his own face. Lockhart can also, apparently, use magic to carve his signature into the Quidditch field.
It is, of course, possible that while Lockhart was once capable of casting these spells, he has forgotten them in his arrogance.