Final Fantasy VII is the best game ever! I may be subjective, but it's my all time favorite RPG and my all time favorite game. It just doesn't get any better than this and if I were to review it, I would give it a 10 out of 10. The graphics may look outdated, but the storyline and materia system are enough to eat up months (for me years) of your life. If you like mythology, you might recognize some of the creatures that you can summon while playing Final Fantasy VII. While some of them are compulsory to get during gameplay in order to beat certain bosses, others are easily missed.

Cloud Strife's Limit Breaks
Level 1:
Braver- Automatically activated. This involves Cloud jumping up into the air and vertically slashing a single enemy. Looks like Cloud’s Deathblow attack.
Cross Slash- Activated by using Braver 8 times. This attack does 3 slashes to a single enemy.

Level 2:
Blade Beam- Activated after killing 80 enemies with Cloud. This involves Cloud slamming his blade to the ground sending a shockwave to the main target enemy. The main blast ricochets off sending miniature shockwaves at the other enemies doing slightly less damage.
Climhazzard- Activated by using Blade Beam 7 times. Cloud slices into a single enemy, then jumps upwards with his sword still in the enemy.

Level 3:
Meteorain- Activated after killing another 80 enemies with Cloud. Cloud spins his blade around then jumps up into the air and creating meteors with his blade which attack all enemies.
Finishing Touch- Activated after using Meteorain 6 times. This involves Cloud creating a tornado with his blade which blows all enemies away. Doesn’t work on bosses of course.

Level 4:
Omnislash- Found in Battle Arena. Get either 64,000 Battle Points on Disk 1 or 32,000 Battle Points on disks 2 and 3 and buy it there. Cloud slashes at random enemies 15 times in total for massive damage.

Final Fantasy VII Special Battle
To get to the URA battle (special battle) in the Battle Arena, first gain 64000 battle points and buy the W-Summon materia. Next get 32,000 battle points and buy Cloud's level 4 limit, Omnislash. Equip Omnislash and talk to the lady at the counter in the battle arena, and she will ask you if you want to participate in a special battle. Beat all 8 enemies and get the Final attack materia.
Note: You must have your Ultimate Weapon equipped to fight in the special battle.

Easy Chocobo Races
During chocobo racing mini-game, hold L1 + L2 + R1 + R2 to increase your chocobo's speed. Hold R1 + R2 to recover your chocobo's stamina.

All Lucky 7s
If a character's HP is 7777 at any time during battle, it will go into a frenzy of super-accelerated, uncontrollable attacks, each hitting for 7777 damage to a random enemy. If a character has 7777 HP at the end of the battle, its HP will be reduced to 1 when you return to the field.

Unlimited elixirs
You can get unlimited elixirs. In the ice field there's a cave with an elixir in it. Grab it but DON'T push the X-button to let the text disappear that says that you've got an elixir. Normally you can't do anything when that message is on screen but this place is an exception; here you can walk out the cave and re-enter and get it again and again...
Note that if you let the text disappear, the item will be removed from the screen and you can't get it again.

Final Fantasy VII Limited Immortality
Connect the Phoenix Summon and Final Attack materia in any linked slot. When your party dies, their Hitpoints will be completely restored. This makes killing Ruby, Emerald, and Sephiroth simple, just make sure you have enough Mindpoints to use the Phoenix Summon. For more punch, add a Final Attack/Knight of the Round Table to the same weapon. Then when you die you'll resurrect and hit back HARD.
NOTE: This method is limited because you can only use Phoenix materia 5 times.

Master Materia
To obtain "Master" materia, you have to master every materia in each category. After you do this, you should go to Bugenhagen's Laboratory and examine each "Huge" materia. This results in receiving all of the "Master" materias. Each "Huge" materia brings forth a different "Master" materia depending on which class it belongs to.

Cloud Flashback
Any time after Cloud comes back to reality from his dream-like state, go back to the Shinra Mansion and into the basement. Head into the room with all of the laboratory equipment. Here, Cloud should have a flashback and this sequence should reveal how they returned to Midgar after the incident in Nibelheim.

Huge Support Materia
On the second disc, the characters learn that Shinra is in the process of gathering Huge Materia, a materia said to be 300 times more powerful than normal materia. There are a total of four and this one can be obtained by entering the code correctly while up the Shinra rocket. (The code is Circle, Square, X, X or OK, Switch, Cancel, Cancel.) Very important note: in order to obtain this materia from the Shinra rocket, you must have obtained all three of the other Huge Materia from the various locations as well. If you have not, then the Huge Materia you obtain in the rocket will instead be one of three that you missed. I'm not sure exactly how the selection process on this works, however, if you were to say, obtain both the Huge Magic and Command materias, then you would obtain the Huge Summon materia from the rocket. If you obtain the Huge Support Materia, you can choose to view it anytime by visiting the second-level of Bugenhagen's observatory after he makes this option available for you. Examine it and choose to get closer to it and it will emit a cold glow. If you have the materia Bahamut and Neo Bahamut in your inventory, they will blend to form the materia Bahamut ZERO, but you will also keep both of them. This is regardless of how much AP you currently have on either Bahamut or Neo Bahamut. Note that you may only do this once. If for some reason, you later choose to dispose of the Bahamut ZERO, the game will not allow you to blend Bahamut and Neo Bahamut again. If you do not obtain the Huge Support Materia, then you have lost your only opportunity to obtain Bahamut ZERO materia as well as unlimited Master Summon materia. However, you can still obtain the Bahamut ZERO spell if you defeat Emerald Weapon and then present the Earth Harp to the traveler in the house at Kalm. You will receive a Master Summon materia, which will allow you to summon Bahamut ZERO, as well as every other summon.

Here's a list of all the Final Fantasy VII summons in a row. Enjoy these beautiful animations: