Since spell casters spend so much quality summoning time with elementals, I like to seem them greatly improved.
In Neverwinter Nights 2 they seem too common. The should be reskined. In other dungeons and dragons video games they are better. I like the big brute looking Earth Elemental in The Temple of Elemental Evil. I like the mischievous looking fire elemental in Neverwinter Nights 1. I like in Baulders Gate 2 having a random chance of summoning an elemental prince.
I like to see different color variants to the elementals. Have fire elementals flames that surround them burn brighter the more powerful he is. Have a lesser power earth elemental look like he his made out of dirt. Have a elder elemental look like he made out of hard earth or rock.
I like to see trail elemental effects for each elemental. Earth Elementals leave a trail of dirt, Fire Elementals leave a trail of scotch marks, Water elementals leave a trail of water, Air leave a trail dust of wind.
Have weather effects effect elementals. Rain is bad for fire elementals. The Desert heat is good for fire elementals. The opposite for water elementals.
10 - A Masterpiece, Genuinely Groundbreaking 9 - Outstanding, a Must Have 8 - Excellent, Recommended to Anyone 7 - Very Good, Deserves a Look 6 - Good, Qualified Recommendation 5 - Fair, Solid yet Unremarkable 4 - Some Merit, Requires Improvements 3 - Poor Execution, Potential Unrealized 2 - Very Little Appeal 1 - Not Recommended to Anyone