My absolute favorites per instrument:
We have very similar taste in what we enjoy playing on guitar. Let me see if I can expand that list with some similar songs.
- Pick me up (Awesome long end solo much like the Richard frampton song)
- Thin Lizzy pack (All around great tunes with some very fun guitar parts)
- My Sharona (Really fun solo towards the end of the song)
- Can't Stop Rockin' (Great song awesome end solo)
- Yes (Just get the pack, most of the songs are great on guitar)
- Poison (Great tune, cool solos)
- Do you feel like we do? (Very long song with tons of solos in between)
- Would you go with me? (One of the funniest country songs on guitar)
- Good Time (Another very fun country song with three solos)
- Godzilla (Classic song with just the right difficulty)
- Child in Time (Incredible difficult solo, but the song itself is top tier)
- Laid to Rest (Really fun song to play on both Bass and Guitar)
- Are you dead yet? (The only song ever released from Children Of Bodom, and it's just fun to play throughout the whole song. Not too difficult)
- Chiron (In my opinion the best song from All that Remains, very fun throughout the whole song with a very difficult solo to top it off)
- What a Horrible night to have a curse? (This one might be too extreme for many, but it's one of the best songs to learn triplet strumming, and it has some really fun ho/po parts and an awesome solo near the end. A huge guilty pleasure for me)
- Ghost of Perdition (A reminder of how sorely we need more Opeth songs)
- Catcher in The Rye (In my opinion the funniest song to play on the Chinese Democracy album)
- Smooth (Overall great song, some really fun guitar parts)
- Both Kansas song (Does have some really tricky parts, but they are both awesome songs to play and listen to)
- N.I.B + War pigs (Black Sabbath classics)
- Stonehenge (Unfortunately you can't buy Spinal Tap anymore, so let's hope Harmonix fixes that for the future)
- You can still rock in America (The second solo brings the song down a bit because it always wrecks me, but the first solo makes up for it. Very fun song to play)
- Rosanna (Classic song with some surprisingly difficult parts)
- My old school (My favorite of Steely Dan on RB, tons of solos with just the right amount of difficulty)
- The Hellion/Electric Eye (One of Judas Priests' best song, fair difficulty)
- Tribute + Metal (Best songs to play from Tenacious D)
- I want it all + The Show Must Go On (I want it all is by far the funniest Queen song on guitar, very underrated song)
- Tuesday Gone + Sweet Home Alabama (Two of my favorite songs from Lynyrd on the guitar, even though some of the solos on the songs are merciless, especially the tapping part on TG that I never seem to quite get)
- Rime of the Ancient Mariner, Fear of the Dark (Fun songs that aren't too difficult by Iron Maiden - bonus Rime has one of the best Bass solos in the game)
- Pretty much everything by Rush. (Damnit, almost all their songs are fun to play on the guitar)
- On the Back of Angels (It's not as hard as you might think, there are some tricky parts near the end, but overall it's a very fun song by Dream Theater)
- I believe in a thing called love (The whole song is just a myriad of fun solos with a really difficulty tapping part towards the end)
-Clint Eastwood (Such a groovy tune with two fun and difficult solos)
-King of Rock (What absurdity is this? Rap in my Rock Band game? Actually, it's a really cool song with almost exclusively solos)
- No Woman, No Cry (My favorite Bob Marley song, a very relaxing song on guitar with a fun solo in the middle)
- Icky Thumb (I won't deny the piano solos are just a cruel joke, but for some reason I keep going back to this song, it's just very fun to play despite its difficulty and the tune is great)
And I can go on, Ozzy have some great songs (Bark at the Moon, Mr.Crowley, No More Tears, Diary of a Madman, Mama I'm Coming Home) Jimi Hendrix has an absurd amount of songs, some of them are really great (If 6 was 9 and All Along the Watchtower). There are of course more songs that has slipped my mind, and I can update this post later if I remember them.
Bonus: Can't be Tamed (If the concept of getting your ass handed to you by a Miley Cyrus sounds tempting)