I am about to upgrade to a new and bigger aquarium and I was wondering on what type ofm fish I should get. Please leave comments and advice about the different types of fish and also the pros and cons about having these fish.

fish in a tank is so subjective. I think tetras a re neat looking but in my tank i prefer guppies. I suggest going to the local pet store you trust with a pad of paper and looking at the fish they have available. write down the ones you prefer and then research the type of environment they each need to see if they are compatible. which unfortunately i forgot to do with my new tank so i am having some territorial problems.

from experiance with this
chichlids - (of which angel fish are part of) are great looking fish and some are territorial if you get 1 stick to an all cichlid tank
guppies - cute and very fun to watch but breed very easily and are very tolerant of different environments
iridescant sharks - very nice to look at, you buy them small but need a very tank once full grown ( can grow to be almost 2 feet long ) with a strong current ( are a river fish)
neon tetras - compared to other fish breeds in mu opinion are a short lived fish but are great schoolers. never get less than 8 in my opinion for a school of them.
Rope fish - a breed of reef fish, snake like with primitive lungs and unless they have a hiding place in the tank they will become escape artists to find a hiding place and can survive i have heard up to 3 or 4 hrs out of water. ( carniverous fish which needs to hunt. feeder snails work great any they don't eaten may help to keep the tank a little cleaner) tend to be nocturnal but will come out and play in the light sometimes.
Pleco's - great tank cleaner, can get very large, will find a place in the tank to hide in during the day and come out to eat and clean at night
algae eater - not to good looking but great for keeping a tank clean i prefer pleco's even thou they can grow quite a bit
Goldfish - (comets, feeder's) nice looking eat alot and are very messy. i recommend getting feeder goldfish to start the tank cycle and they are 1 of the cheapest fish available. some people i know recommend mollies for this but i find them so nice looking i never want to take a chance on losing any and with a starting tank it will happen.
Mollies, barbs and swordtails - there are some real nice looking breeds of these available but i am still learning about them so cant offer any advice on these.

Hope this helps you