I'm going to try and correct some song names (or alternatives) as best I can.
1. Super Smash Bros. Brawl Theme (It's not the original, now is it?)- It is called the theme of Smash Bros even in melee's theme in the mini album. For consitancy, this remains, even though the song is different.
5. Super Mario Land Dungeon Theme (Easton? What's that? @_@)- Easton is the kingdom where it plays. There are 4 kingdoms
34. Legend of Zelda Main Theme (Meh, the welcome seems weird to me.) It is a differentiator
48. Twilight Princess Hyrule Field (Meh, full version of name.) Unnecessary
54. Metroid Ending (The End of Metroid works fine though.)It works fine, as you said
55, 59, and 60 just have the word Theme attached on. nah
65. Yoshi's Story Athletic Remix (or Yoshi's Island Athletic Remix, I forget which one.)It is not athletic, that would be donut lifts and the Dial-O-Matic
67. Touch the Flower Garden (Touch means Yoshi's Touch & Go.) THAT I like.
70. Legendary Machine (That's what it's called in Kirby's Air Ride, correct?)
76 and 77 have the word Theme attached on. Nah, it be fine.
86. Area 6 (From Star Fox 64.) That specific version is from Star Fox Command
92. Area 6 Remix (See above.) See above
108. F-Zero X (Is the name of the game.) It is the menu theme, a literal welcome!
112. F-Zero GX (See above.) See above
135. Pikmin 2 (I don't like the "Welcome to" part.) Too bad
140. Pikmin Theme- see below
141. Pikmin Title- Now we are nitpicking
165. Underworld (Is what the area is called.) It can be called that.
166. Kid Icarus Title (Angel Island Story? Meh.)- The title screen says this!
168. Kid Icarus Medley (Right?) Nope. It reflects what it is, plain Kid-Icarus
170. NES Medley (Famicom is soooo Japan.) That is because it IS japan
188. Mario Sports Tour (Why would there be a family? Meh.) THAT is the way it is in japan
204. Yell Dead Cell (Or at least, from what I've heard, Dead Cell tis a part of the title.) it is the mere area
206. MGS4 Love Theme (You made it look so complicated.) nit-picking
212. SSB Credits (Mhmm.) Not what it is in the game
213. SSBM Menu (Sounds a LOT like it anyway.) See above
214. SSBM Theme Remix see above
215. Master Hand Final Destination (Noticed the empty space of music near the beginning? Put Master Hand's laugh there. It works perfectly.) see above, and NO laughs
237. Corneria (There is no other song title like this.). it refers to it being from a previous game
250. SSBM Battlefield (You made it look complicated again, so I just did this.) Nit-picking
252. Hyrule Temple (That's what the stage is called.) see 237
253. SSBM Final Destination (Not So? I don't get it really.) It is not THE final destination anymore is it? Nope.
291. Meta Knight Victory (He is only called Sir by his slaves... are you his slave?

) Nope, but the title remains though you got the numbering off
294. R.O.B. Victory (Who is Gyromite? Isn't R.O.B. it's name?) Gyromite is the series the song is from
299. Trophy Obtained nope
300. New Playable Character nope
301. Coins Obtainednope
302. Special Message nope
303. Stage or Game Mode Unlocked nope
I don't mean to be rude in any way, but this is what I think about the song's actual names, and just fixed it up to make sense a bit.
Fixed.