I could be here all day with this, but here are several songs that fit into the category:
Macklemore and Ryan Lewis-Thrift Shop, Can't Hold Us, Same Love
Lorde-Royals, Team
City High-What Would You Do, (this group have been forgotten, but they were big back in the day and that second song piggybacked from their recent single's success)
Flo-Rida-Low, In The Ayer
Gym Class Heroes-Stereo Hearts, Ass Back Home
Taio Cruz-Break Your Heart, Dynamite (his 3rd single flopped and shortly disappeared after that)
Jay Sean-Down, Do You Remember
Jason Derulo-Whatcha Say, In My Head, Ridin' Solo
Soulja Boy-Kiss Me Thru The Phone, Turn My Swag On
T.I.-Whatcha Know, Why U Wanna
Ke$ha-Tik Tok, Blah Blah Blah (there's no way a song like "Blah Blah Blah" would've been a hit if it wasn't for "Tik Tok's" success, there's nothing good or memorable about it)
Sean Kingston-Beautiful Girls, Take You There
Kelly Clarkson-Since U Been Gone, her consecuent singles off that album
Bell Biv DeVoe-Poison, Do Me!
Color Me Badd-I Wanna Sex You Up, I Adore Mi Amor, All 4 Love
Kris Kross-Jump, Warm It Up
Arrested Development-Tennessee, Everyday People, Mr. Wendal
Santana-Smooth, Maria Maria
all of Flo Rida's singles from "Wild Ones"
Will Smith-Gettin' Jiggy Wit It, Just The Two Of Us
Rick Astley-Never Gonna Give You Up, Together Forever, all of his other top 10 hits after NGGYU were hits because of that song, but have all been forgotten, he's actually mistakenly regarded as a one-hit wonder
Ace Of Base-All That She Wants, Don't Turn Around, The Sign
Lisa Lisa and Cult Jam-Head To Toe, Lost In Emotion
New Kids On The Block-The Right Stuff, Hangin' Tough
Hunter Hayes-Wanted, I Want Crazy
Chris Brown-Look At Me Now, She Ain't You (LAMN was his major comeback single, and "She Ain't You" was only as big as it was because of it, and has been forgotten with time)
Big Sean-My Last, Dance A$$ (only reasonn DA was big was because of Big Sean's success from his previous single, and that Nicki Minaj was involved in the song
Jesse McCartney-Leavin', How Do You Sleep
Milli Vanilli-Girl You Know It's True, all of their singles that followed until they were caught for lypsinching which ruined their careers
C&C Music Factory-Gonna Make You Sweat, Here We Go (Let's Rock 'N Roll), they're virtually the same song and the latter was only big because of GMYS
Black Eyed Peas-I Gotta Feeling, Imma Be and Rock Your Body (the latter two singles wouldn't have been major hits if not for "I Gotta Feeling", and both songs have been forgotten as the years have gone by
Black Eyed Peas-Don't Phunk With My Heart, My Humps
Pussycat Dolls-Don't Cha, Stickwitu (the latter was only hit due to the success of their previous single, and has been all but forgotten about)
Shaggy-It Wasn't Me, Angel
R. Kelly-Ignition, Thoia Toing (there's wasn't much memorable about that song and wouldn't have been a hit if it wasn't "Ignition")
50 Cent-Candy Shop, Disco Inferno
Ciara-Goodies, 1,2 Step
Aloe Blacc-"The Man" wouldn't have been a hit if it wasn't for "Wake Me Up", and I doubt Aloe Blacc will have further success from here on out.
Jay-Z-Empire State Of Mind, Young Forever
PSY-Gangnam Style, Gentleman ("Gentleman" only reached #5 because it was piggybacking off GS' success)
LMFAO-Party Rock Anthem, Sexy and I Know It
Wiz Khalifa-Black and Yellow, Roll Up ("Roll Up" wouldn't have been a big hit if not for B&Y)
Bobby Brown-My Perogative, Every Little Step (while MP has had a lasting appeal, ELS has become dated, and only in 1989 would a song like that hit coming off the heels of "My Perogative's" massive success
Nelly Furtado-Promiscuous, Get It Right
Adele-Rolling In The Deep, the other singles released after from "21" (none of Adele's singles after "Rolling In The Deep" would have been as they were if it weren't for it's surprising massive success)
Pharrell Williams-"Happy" wouldn't have been as big as it was if it wasn't for "Get Lucky" and "Blurred Lines" success. Prior to that, Pharrell had pretty much become irrelevant at the start of the 2010's.